In our system it actually doesn't matter if they have no legal teeth. If your former employer wants to spend money to take you to court to attempt to enforce a non-compete, you'll be forced to spend tens of thousands of dollars (if not hundreds) defending yourself.

It doesn't matter if they'll eventually lose. Just as long as they can play legal chicken with you and get you to give up because you don't want to waste all your money on lawyers defending yourself.