Alarmed by the aggressive timbre of some of Scotland's pro-independence debate, the writer JK Rowling has donated £1m to the No campaign. Or "Bitter Together", as some of us like to call it. Her point was proved as Scottish separatists swarmed all over social networks, hurling abuse in response to news of the donation. Scoundrels, all of them, with patriotism their last refuge. (That's the coinage of Englishman Samuel Johnson, recorded for posterity by a Scotsman, James Boswell. Which is nice.)

Rowling is right on this. The kneejerk, sentimental, victim-mentality, Hate-the-English-colonisers patriotism that some Scots display is pretty much the most unappealing of Scotland's products. There is no more abject argument in favour of Scottish independence than naked, angry nationalism. The paradox is that only independence can rid the country of that pathetic strain of chip-on-the-shoulder, tribal narcissism. Even then, it would take a while before they stopped blaming Westminster for any difficulties that appeared resistant to the instantly cleansing magic of home rule. That, however, does not mean that there are no good reasons for Scottish self-governance. There are plenty.

It's no surprise that Rowling is a unionist. She is a high-profile Labour supporter, and Labour loves the union. Of course it does. Labour supporters are fond of pointing out that there are more pandas in Scotland than there are Conservative MPs. Without Scottish seats in Westminster, Labour would find it much more difficult to win general elections in the south. That's the main reason why many people in England dread an independent Scotland, too.

Scotland has long provided a bulwark against English Conservatism, which is why it may look as if the Tories are acting out of principle in supporting the union, rather than their usual self-interest. They are not. Westminster-based, two-party politics suits the Conservatives, because even when they are not in power, their opponent, Labour, only gets in when it has convinced the City of London that it has nothing to fear from them.

It's so ironic that the last Labour government fell because of the financial crash, because the unfettered, free-market City was everything that a truly social-democratic government should have guarded against. And it's ironic that Labour is losing support in England to Ukip. There was no greater cheerleader for open borders than the City of London, who wanted to have the wealth to attract the greediest financial predators and the low, bottom-end wages to ensure that they didn't have to spend money that could be invested offshore on paying a decent wage to those who served them. The limitations of an adversarial system of Westminster government are stifling enough in England. In Scotland, when one of those two parties barely exists, yet still has long periods of rule, it's actually abusive.

Rowling argues that in an independent Scotland, the collapse of the Royal Bank of Scotland would have bankrupted the country, because it was bailed out by central government. But she forgets that Scotland never voted for Thatcher's Big Bang deregulation of the City, let alone the vandalistic deindustralisation of Scotland that came hand-in-hand with it. Also, while Rowling may have been an admirer of New Labour, many Scots would rather have voted for a Labour party that didn't squander its landslide by continuing to leave financial services as a law unto themselves. Yes, New Labour was dominated by Scots. But it was the English the Labour big beasts had to woo, not their Scottish constituents.

The truth is that the SNP are only in power in Scotland, and able to offer this referendum, because Scotland got so fed up with being part of a two-party state that is more like two one-party states shackled together. Labour thought it could afford to be complacent about Scotland, especially after devolution. It is finally realising that that was a huge mistake. In recent decades it has become horribly apparent that Scotland's main political function in the union is to provide democratic cover for a UK that is ruled for and by the home counties, whoever is in power. If you actually lived in Scotland in the grotesque and awful Thatcher years, under that repellent caricature of democracy – well, it really sucked. Devolution helped, in a limited way. But we are only where we are now, first, because Westminster refused to take seriously the idea of granting Scotland fiscal autonomy within the union, and second, because the north of England remains so sleepily opposed to devolved government itself.

If Scotland leaves the union, the collapse of political stability in England will accelerate. A pro-independence vote is a pro-democracy vote, and it's a shame that it falls to the Scots to shake England from its slumber. What the UK needs is stronger local government and a smaller Westminster that does not concern itself with micromanaging the lives of people it neither understands nor cares about. With Scotland gone from Westminster, that would become much more apparent in England than it already is. Scottish independence would change England more than Scotland. If England showed a bit more willingness to change, there wouldn't be such a problem.

I'm no Scottish nationalist. But I am enthusiastic about responsive and democratic government, transparent and accountable, for all people, everywhere. I'd have preferred for that to be achieved, for Scotland, within the union. But it just isn't happening. The fact that "devo max" was not offered as an option in this referendum (blocked by Cameron) is proof that Westminster simply doesn't want to improve UK democracy. I'm certain that if Scotland was forced to go it alone, then it most certainly could deliver a more democratic system of governance. For one overwhelming reason: it couldn't do worse.

Like many Scots, I am irked by arguments from the No campaigners that Scotland isn't capable of independence. Really? Our education system has always been separate, and it's doing fine, thanks. In fact, more people in Scotland have had higher education than in the union as a whole. At the risk of sounding like a patriot, I'll point out that Scotland isn't just the best-educated country in the union, the Office for National Statistics reckons it's probably about the best-educated country on the planet. That's where England is trying to head, right?

Yet, despite Scotland's advantage in intellectual capital, there is much scaremongering from No campaigners about the ability of a Scottish economy to flourish. Rowling is right to say that the Yes campaign is unwilling to engage with these arguments. But why should it? Scotland unequivocably wants responsibility for its own tax and spending decisions, for better or for worse. It is not afraid of failure. A recent poll showed that, given the choice between fiscal autonomy and full independence, 61% would choose the former. Given the choice between fiscal autonomy and the status quo, that figure rises by 1%.

Scotland wants to be responsible for its own financial affairs. Finger-wagging paternalists who say we couldn't manage fail to see, first, that their attitude is annoying, and, second, that it is not about being rich or poor, successful or unsuccessful. It is about standing or falling because of choices you have made yourself, not because of choices that have been imposed on you. It is a psychologically healthy and mature position. I can think of no other situation in which a willingness to be responsible for your own budget would be so discouraged and denigrated in a group of people. At their worst, Scottish nationalists are as creepy and pathetic as EDL members down south. But self-governance isn't about that. It's about believing you can arrange matters in a way that will be inspirational to others – shine a light in a world that is a bit of a mess. Do I believe that, given the tools, Scotland is capable of making such a contribution? Do I believe it should have the courage to try? I do. Yes.