Ambiguity on Brexit has spawned many Jeremy Corbyns, and they all lie in the eye of the beholder, depending on political allegiances, frustrations and hopes. There is the cunning Corbyn: secretly a hard Brexiter but who doesn’t want to alienate remainers. There is the craven Corbyn: pro-remain but too afraid of Brexit populism to be too open about it. There is also another pro-remain version: coy Corbyn, playing a game of political subterfuge, winking at remain Labour voters and waiting for the government to be completely worn down before he swoops in with a campaign for a second referendum. Then there is calm Corbyn: above all else, a democrat and a respecter of the will of the people, so he will grit his teeth and think of England.

It is likely that none of these Corbyns exist. He has sent signals that can be interpreted in any of these ways. He has been a strong supporter of withdrawal from the single market, but still won’t come completely off the fence on the matter. He consistently denies interest in a second referendum but also indulges speculation, saying late last year that he would vote remain in a second round. When confronted, he won’t rule a second referendum out.

Why all the uncertainty? Perhaps the more straightforward explanation is that Corbyn simply doesn’t care about Brexit enough to engage with it robustly one way or the other.

But “indifferent Corbyn” fits no one’s narrative. He cannot be smeared by Blairites as a parochial anti-trade ideologue leading his naive young remain supporters down the Brexit path; he cannot be lauded by the party faithful as a wise man with a plan, and he cannot be painted by the right as an open-borders-loving softie.

Even his most consistent positions are not necessarily a smoking gun. Voting for article 50, sacking a shadow cabinet minister who called for another referendum, and urging MPs to abstain from votes that make the government’s life harder need not indicate covert support for Brexit. They may be attempts at asphyxiating a combustible issue, one which could be used against him by Brexit-supporting opponents.

Sure, Corbyn is interested in Brexit, but only insofar as it is a tool with which to club Theresa May and the Tories. Like last week, where at prime minister’s questions he nailed her on the weakness of her negotiating hand given the divisions within her own party.

But he doesn’t always show up. In fact, he has received repeated criticism for failing to challenge May in parliament. And his on-off enthusiasm over Brexit exposes the things Corbyn really does care about: austerity, rampant capitalism and inequality. As a frontbench Labour MP told me, Brexit is quite far down his list of priorities. His view of challenging the government does not involve spending lots of time bogged down in technical detail about the Irish border.

And that’s fine. Indifferent Corbyn is not necessarily a bad thing – the reason he became popular in the first place is because he had not been swallowed up by the dulling obligations of technocracy, nor did he have the detached tone of other Labour figures who lost the pulse of the party’s voters. These same figures, incensed by Brexit, still do little but scold leave voters for their ignorance and agitate for a second referendum – despite the fact that there’s little polling to suggest there is a popular appetite for one.

Even if they are right about the impossible technicalities of leaving the EU, the “it’s all above your head” argument isn’t really a vote winner. There’s a reason it didn’t cut through first time round. Corbyn’s strength remains in his ability to focus on issues such as job security (job losses due to businesses relocating over Brexit uncertainty was his focus in last week’s clash with May). Brexit fatigue also works for him. In this month’s English local elections there was a distinct “bins over Brexit” vibe.

But Corbyn’s changeability and inconsistent engagement on Brexit also plays into what could be seen as his greatest weakness: that he is only a flagship values politician, valuable on the back benches but not interested in the mundane daily grind of government. Corbyn is NHS, austerity, nationalisation, social housing. He is Stop The War and nuclear disarmament. As far back as the referendum campaign, Corbyn’s listlessness over Brexit fed the impression that he was lukewarm and not leadership material.

I sympathise with indifferent Corbyn. Brexit came out of the blue, within a year of his election as party leader. It hijacked a space that could have been utilised for returning Labour to its socialist roots and mounting a credible challenge against the Tories, which was all he ever wanted. After all these years in the wilderness he finally had a clean shot, and Brexit got in the way. But now it’s here, he has a chance to burnish his leadership credentials, be forensic, adopt a firm stance (be it hard or soft Brexit) and prove he can do detail as well as drama.

• Nesrine Malik is a Guardian columnist