There was no single moment when things went horribly wrong in Venezuela. The sitting President Nicolás Maduro is the legitimate progeny of the late Hugo Chavez, just as Stalin was the legitimate heir of Lenin.

Whereas the Russian state founded by Lenin contained "the germ of all Stalinism...at its beginning", as Victor Serge put it, so Hugo Chavez's Bolivarian Revolution contained the genesis of today's collapse into economic catastrophe and dictatorship from the start.

This is not a revolution betrayed. It was obvious a decade ago that the 'Bolivarian Revolution' was rotten, and this was no less true because governments in the United States behaved appallingly towards Venezuela.

As in Cuba, the northern neighbour that El Comandante Chavez viewed as a model for his own country, imperialist belligerence from the north was more of an excuse for clamping down on dissent than a reason for it.

The real transformation has occurred in the minds of the Venezuelan government's depleted band of foreign admirers. For the most part they have sunk into stupefied silence.

At one time Venezuela stood as proof that 'another world is possible', whereas today it exists as a perpetual embarrassment to the British left, the political equivalent of a bilious uncle who falls and soils himself in drink-sodden disgrace. Something unpleasant is happening but it is best not to talk about it.

Venezuelans are of course not afforded that luxury. "I talk with my family and close friends who live in Venezuela via telephone or Skype or WhatsApp. Not a day goes by in which they don't break down in tears," Edmundo Bracho-Polanco, a Venezuelan lecturer in communications and media at the University of Westminster, told me recently.

A global fall in the price of oil, together with the gross mismanagement of the Venezuelan economy, has led to this economic collapse and the widespread immiseration of the people. For all the initial promise of Chavez's rise to power, ragged and emaciated men and women today walk the streets of Caracas, rummaging through bins in the hope of uncovering a morsel of food, while government-sponsored armed gangs – the 'colectivos' – dish out violence and intimidation against political opponents of the government.

Anti-government protests have now been going on for three months in Venezuela, in the largest wave of unrest since 2014. On 30 July, the government will hold a so-called 'constitutional convention', in what many suspect is an attempt to rewrite the constitution and consolidate power.

The government has already travelled a considerable distance down the road to dictatorship. Several opposition figures languish in detention without charge, and according to Amnesty International the Venezuelan government is "using the justice system to illegally increase persecution and punishment of those who think differently".

I have written several articles like this over the years. Each time the condemnation of the Venezuelan government by various human rights organisations has grown louder, to the point where finding someone on the British left who backed Hugo Chavez and his successor Nicolás Maduro has become a bit like searching for a branch of McDonald's in Havana.

Those who were vocal in the past have melted into the air like steam emitted from the spout of a kettle. Their vicarious hopes, projected onto the citizens of a poor and benighted country, have been buried by a collective amnesia, the "great forgetting" as the blogger Jack Staples-Butler has written.

There is little point in a round of 'I Told You So's' directed at those who once saw Venezuela as socialism's great hope. Nor is it useful to declare hubristically (as conservatives invariably will) that 'this is how socialism always ends'.

Socialism is – or at least it ought to be – about extending democracy beyond nineteenth century confines and into the economic realm. There is nothing inherently 'totalitarian' – that frightful adjective which surrounds every attempt at improving the lot of the majority – about giving workers greater control over the seemingly unstoppable economic forces which exert control over their lives.

But if socialism means anything at all it ought to mean making society more rather than less democratic. On that score Venezuela has singularly failed. As the Bolivarian Revolution has matured, opposition party figures and human rights activists have increasingly ended up languishing in the country's jails. Independent-minded trade unionists have joined them, while the neutrality of the judiciary has been destroyed.

Even back in 2011, Amnesty was warning that those critical of the government were being "prosecuted on politically motivated charges in what appeared to be an attempt to silence them". The country was at the time being lauded by sections of the British left as a model that socialists ought to lend their support to.

Berating those who got Venezuela wrong would be pointless. But it is fair to ask whether any lessons have been learned from the tragedy.

Beyond the understandable exigencies in the aftermath of the anti-democratic coup of 2002, why have opposition voices been silenced? Why did production collapse in several Venezuelan sectors soon after industries were nationalised? Has a mighty state with its tentacles in every area of Venezuelan life really given the country's poor more control over their destiny?

Or perhaps to even ask such questions on the British left is to automatically consign oneself to the camp of reaction. Nevertheless, there is something distasteful in celebrating a movement when times are good but disowning it when its unpleasant features come to the fore.

Without self-criticism, very little exists to stop things turning out the same way next time.