If the residents of Neo Bankside had won their legal battle against Tate Modern's rooftop viewing platform, it would have set a dangerous precedent for London, says Owen Hatherley.

It's not often that a judgement of any kind in Britain goes against the interests of private property and in favour of the untrammelled enjoyment of a public space. For that reason if nothing else, anyone who actually enjoys living in cities should applaud Tate Modern's victory over the residents of Neo Bankside.

In response to people actually using the 10th floor viewing platform in the Switch House, Herzog and de Meuron's monolithic brick extension, residents of these three towers of luxury flats – built when the extension and its viewing platform had already received planning permission – had tried to get it closed, citing the alleged invasion of privacy that came with people being able to see inside the winter gardens of their flats.

Surprisingly, if entirely reasonably, the judge in the case ruled that they could do something very simple: get some curtains.

If it had gone the other way, the precedent set would have been alarming; why not close the public steps up to Wren's Monument, in case anyone using it can see inside the dealings of city office blocks? But it's worth reflecting on how we got to the situation where the residents actually thought they had a case.

If it had gone the other way, the precedent set would have been alarming

Tate Modern was the spur for an extremely radical transformation of the London Borough of Southwark. A couple of decades ago, despite its partly central location, this borough had a surplus of council housing, and a riverside made up mostly of disused industrial buildings and warehouses. It was in places very poor, as it still is.

But then came the new Tate, with its monumental turbine hall carved out of Giles Gilbert Scott's Bankside Power Station, and then City Hall, the Greater London Authority's rented home. Between them, all along the river and then moving inland at the Elephant and Castle, dozens of new speculative then high-rise blocks popped up, including Neo Bankside.

With these, Southwark's strategy shifted towards the dubious pseudo-science of trickle-down economics. As Enrica Colusso's film Home Sweet Home details, rather than being an inner London borough whose purpose was to house and aid its largely working class population, Southwark re-imagined itself as a central London borough, whose purpose was expansion and growth.

Initially, that was supposedly going to pay for more and better social provision, but what has resulted instead has been a net loss of council housing stock and a massive rise in housing need. So far, so familiar. But the typology thrown up by this – the speculative flat, the stunning development – is a strange one.

The wealthy do not like to be reminded of the proximity of the poor

In his book on Boris Johnson's architecture, Nincompoopolis, Douglas Murphy argues that there's a certain cultural cringe in the way London presents itself. The capital's dissonant, bombed-out and rebuilt townscape cannot compete with the epic vistas of Paris or Manhattan, so it has to constantly rethink its "offer" in order to retain the "high-value" individuals that a world city allegedly depends upon.

So when the industrial River Thames became a linear city of private luxury flats, they had to go some considerable way in distinguishing themselves from everything around them. Neo Bankside, for instance, may have the Tate as a neighbour and St Paul's opposite, but there are council tenements barely a minute's walk away.

The wealthy do not like to be reminded of the proximity of the poor, but the London County Council's planning policies built them into the city pretty much everywhere except Mayfair and Belgravia, rather than dispersing them into the Banlieue as did Paris. So exclusivity, elevation, aspiration, distinction, are stressed in the design of each new tower, and are rammed home in the marketing.

The notorious Redrow American Psycho advert of 2015 was a particularly lurid – too lurid – case in point. One of the design aspects that helps the marketing along is the view: the floor-to-ceiling, dramatic vista of a glittering metropolis. In the Redrow advertisement, this view is presented as the reward for all the hard graft of working in financial services – sip your glass of wine as you look over the city, which you have now conquered, and which you survey as its master.

They've managed to do something unique in London, in giving it a free, public high-rise view

It's an ironic reversal, as anyone who remembers the discourse around housing in the 1980s and 1990s, will recall these sorts of views being covered up in the renovations of council towers, both by councils and by residents, with floor-to-ceiling windows made smaller and residents getting the net curtains in. Rather than one of all-surveying triumph, the council tenant's experience of the same view was imagined to be alienating and vertiginous.

In any case, the point of those windows in something like Neo Bankside is that they're meant to be looked out of – they're absolutely not meant to be looked in on. In the residents' reaction to the Tate viewing platform, there's a real sense of embarrassed entitlement: "I'm supposed to look at you, you're not supposed to look at me!"

While it was hard before to see the Tate Switch House as a particularly public-spirited building, with much of its floor space given over to function rooms, it's clear now that they've managed to do something unique in London, in giving it a free, public high-rise view. Most of the public places where you can actually see London are the rus-in-urbe skyline views of its parks – Parliament Hill, Primrose Hill, Greenwich Park – but here is a view where you can really see up close the sort of a place you live in. Before there was only the Monument, with its endless flight of steps. The high-security, booking-only Sky Garden of Rafael Vinoly's egregious Walkie Talkie definitely doesn't count.

Now, you can go to a space in the heart of the city where anyone, absolutely anyone, can go and have a good look at it, at its full extent – a view as essential to understanding it as the view from the ground. And for once, the rich can't stop you.