Because it's easy. It's easy to arrest someone who lives in society, has an investment in it, owns property, and wants society to continue operating. You just go to their house, their job, pull over their car, etc. If you don't own a house and don't have a job and drive a stolen car, there's no leverage. It's like trying to catch a feral dog, there's no negotiating, it's just a dangerous physical confrontation.

Police enforcement is therefore exponentially more effective against the law abiding. It's the streetlight problem writ large.