Buffalo is probably the worst example you could give of that concept. When things get torn down in Buffalo, nothing ever gets put back up. There are literally acres of urban prairie and blight across that city. The city is one step above Detroit, and even that is only because they have a billionaire who cashed in on the fracking boom who loves hockey and loves to build stuff.
If you want to use the analogy of tearing stuff down in the hopes that something better might be built, keep in mind that the new item might never BE built. Destroy the Republican Party and, given current demographic trends, there might not be the appetite to rise against the Democratic machine.
I simply found a cool video. I could not personally be found remaining in a stagnant place like what you say about Buffalo. My mother's family left NY in 1928.
Out here in California, with all of our perceived problems, old gets torn down for new. Jobs, revenues, taxes, fun things to see and do. Did I fail to mention weather? high 70 F the last few days.
Here is a big real estate development project, called Pacific City. Shopping Center Dining, and 500 luxury apartment units.
Before they built this, they had to tear down several other things.
http://www.gopacificcity.com/