They do. Law enforcement resources are hopelessly and perpetually under-allocated. One can fly under the radar for a long, long time, so long as they don't start openly and flagrantly beg the "long" arm of the law to pay attention to them.

If you're both an under-privileged minority and you live in a heavily-policed area, this may not apply to you. But everyone else can operate based on a pragmatic assessment of the likelihood of getting caught.

Start a business that violates the law, so long as it's not one that invites the cops to bust through your doors, (i.e. drugs) your ability to operate will rest on society's judgment.

"Should be allowed" is language that hinges on a belief that the law is an inviolate arbiter of right and wrong. It is not. Crowd-sourced judgment is that arbiter. The law is just that arbiter's proxy.