Boulder's constraints are almost entirely political. You could even build up in the mountains if you really wanted to (but that would be awful). There's tons of land in a green belt around it that's quite buildable, and of course most of the city is your basic single-family home western american town with a ban on apartments or building even human-scale 2/3/4 story housing.

eigenvector's point still stands.

You choose Detroit, or Cleveland, or Birmingham, or whatever and you completely distort their local economy.

Detroit I'm sure has plenty of real estate waiting for a good use. Yes, a lot of the blight has been razed, but my understanding is that there's still plenty of underused urban buildings.

Playing devil's advocate to your devil's advocate play, isn't it better when a tech giant opens up a new campus in a not-so developed area? This brings new jobs, raises equities, increase resources, etc. We're talking places like Austin TX, Portland OR, etc. They are at a sweet spot today. They should stop here.

Because there's a fine line where it has to stop otherwise it becomes a disruptive machine like the Bay Area and NYC.