Did we, though? Middle-income “towers in a park” renewal schemes went over quite well, and remain popular places to live today – even in America, where all the incentives point towards the exact opposite. (In other societies, “sterile” but private high-rise areas are often the absolute choicest addresses.) What “didn’t work out so well” was warehousing poor people without choices in isolated vertical slums, and that had little to do with the design of the place.
Demanding that urban places be perfect (while giving continued suburban sprawl a pass) is a terrific recipe for ever more exclusionary, expensive cities that are increasingly irrelevant as economic activity shifts to the suburbs. That’s exactly the experience of US cities over the past 20+ years: we’ve become zoning-review, design-review, historic-review, affordability-review, environmental-review, stormwater-review, streetscape-review, community-input-review perfectionists about allowing any new buildings. That perfection miiight be possible… but costs a lot of time and money, and then once it’s done it’s (a) out of date and (b) so dang expensive that everyone complains about that. Meanwhile, 90% of new houses are built in sprawl (getting waved past all of the above reviews!)… and oh, the planet’s on fire.
How do I know? I live in a 1960s urban-renewal building in DC, surrounded by new shiny things that had to undergo decades of reviews from dozens of different agencies and as a result ended up, in the words of someone else here, “sterile and a bit boring.”
Cities are living things; they don’t have to be perfect the first time around. Places can and will change after the first draft; the most important thing (and speaking as a perfectionist writer who’s procrastinated on stuff for decades!) is to get the dang words outta your head and onto paper.