Earlier quoted context omitted.
take a walk through Wrigleyville in Chicago on a Friday night, where you can see an endless parade of taxis picking up an endless parade of drunk students. But isn't this supply meeting demand? If there were too many taxis, wouldn't the supply eventually cull itself when nobody can make enough money?
The subtext behind an invocation of Wrigleyville is that drunk bar clientele from outside the area makes it difficult to live in. Wrigleyville is a running joke among people who live on the north side of Chicago.
There are completely similar places were ("drunk bar clientele from outside the area makes it difficult to live in") without any taxis (e.g in Amsterdam or Barcelona). Or places where the drunks prefer to drive (don't ask). In a dense city people can just walk there from a different area, or use the metro.