I think they do understand most laws, but they know the RTP don't do their job, so carry on regardless, Thais do not like being told what to do, each individual thinks they know better than anyone else, and the fines here are pathetic, a huge % of the population have illigal weapons/guns. Same with any crime here plead guilty and get a 50% discount on any jail time, so that's just 10 years for murder minus time off for good behavior.
The whole law system is just BS. IMO