That sort of enforcement is a very localized thing, I suppose. I have never seen a cyclist pulled over here in PA. What sort of fines are involved and how do they compare with fine a motorist gets for running the same stop sign? I'd bet that the fine the cyclist pays is a lot lower. And, if he gets too many tickets, what happens? Does he lose his bike rider's license? What? No such thing? Well, then would they pull his driver's license (if he had one)? I doubt it.
I used to work with a guy who was such a lousy driver that he could never keep a driver's license for any length of time. So, he rode. And, guess what? He rode the same way he drove. He had no car, and paid no insurance, but once I watched him ride diagonally through an intersection of two 4-lane roads at lunch hour, and it was like something out of the Keystone Kops.
Responsible people are responsible people whether they drive or ride. It's the idiots that cause problems regardless of their choice of vehicle. My gripe is that the burden of responsibility falls more heavily on the motorist than the cyclist. If I have to swerve to avoid a cyclist and hit another car, I would be considered at fault for that accident for "not keeping my vehicle under control at all times".