But it would be pretty sad to grow up in a working class family and then be forced to move away from your hometown at the age of 30 because rent had grown faster than your ability to generate income.
There are trade-offs everywhere. The reason these crazy cycles continue is because people refuse to accept alternatives. If more people said "screw you guys, I'm leaving" to expensive cities, the cities would start to become cheaper.
There are also cities that die off because the industry in them goes away. Are we going to force them to stay where they are so that they don't end up bidding up prices, driving kids born in Oakland out of Oakland?
And while Silicon Valley and the greater NYC area are something of exceptions, you get out of the urban cores of somewhere like Boston/Cambridge and housing prices go down fairly quickly except for some particularly upscale towns.