My latest column argues that DC needs skyscrapers. A few followup points—
One: As Josh Barro says, the Height Act is really just scratching the surface in terms of problems with DC real estate development law. Particularly outside of the Central Business District there's a weird kind of Calvinball about what the rules actually are. This is a hassle for DC developers, but ultimately protects them from competition because it's very hard for outsiders to break into the market. That said, I really do think the CBD matters most and here the basic issue is pretty simple—rinky-dink buildings on valuable lands.
Two: People like to bring up Paris which only has one skyscraper in this regard. Paris is lovely. Failure to knock down Paris' historic structures and replace them with modern skyscrapers is economically costly, but it has a clear aesthetic value. The value of preserving the DC CBD's boxy postwar office buildings is much less clear to me. Paris is also incredibly dense, containing more people per square mile than New York City, Chicago, or any other substantial American city. Paris has very narrow streets, a very high lot occupancy ratio, relatively little in the way of urban parks, and apartments that are extremely small by the standards of the 21st century United States. So note that even though Paris has no skyscrapers, it's also the case that huge swathes of Paris would violate "width of the street + ten feet" kind of rules. Long story short, applying Paris-style building heights to DC conditions gets you a population density that's closer to Fargo than to Paris.
Three: Someone argued to me that taller buildings would overcrowd Metro. I tend to see this the other way around. Taller buildings would provide the tax base necessary to build things like a Separated Blue Line, some form of north-south Brown Line, and other upgrades. This is one of the ways in which density is win-win. More buildings would support more Metro lines which would increase the value of existing Metro lines and boost ridership. More ridership on existing lines would financially support more frequent off-peak service, which again would make all the stations more valuable.