Cats don't particularly need exercise, are small, tend to be able to entertain themselves, and for whatever reason, are easier to get permission to have in apartments[1]. So if you're a city person, it's magnitudes easier to be a cat person, if you're going to have pets at all. City people are more liberal than country people, on average.

[1] I cannot stand litterboxes, hairballs, or cat urine, so this baffles me...