It's certainly undeniable that skyscrapers can be a cheap way to warehouse people, as, for example, Cabrini Green demonstrated in Chicago. Glaeser complains that Napoleon III's height limitations on Paris (basically, the core of the city is all six stories high) has meant that tall buildings have gone up only on the periphery. But he seems to miss the point that goal of the rulers of Paris is to keep peripheral people on the periphery, where they can amuse themselves setting fire to cars without pestering the real Parisians.
In general, it's hard to get American middle class families to live in high rises because, outside of Manhattan, without restrictive zoning it's hard to get a high enough percentage of middle class children together in one spot to dominate a public school. For example, Glaeser celebrates the reasonably cheap highrises along Chicago's lakefront, but they seldom have "good" schools, in contrast to certain thoroughly gentrified districts of three story buildings. Restrictive zoning is crucial to "good" public schools, but you aren't supposed to talk about that.
As for business, yeah, sure. And yet ...
Moreover, most people seem to like the campus layout best. In particular, engineers seem to like nature a lot. I'm having a hard time thinking of any skyscraper famous for being full of engineers. I'm sure there must be some, but it's funny how few there are.