The WTS always talks about how wrong it was for the Pharisees to make an endless number of rules. But the WTS is guilty of the same thing. You can't have a beard... you can't watch rated R movies... you must report your field service activity... you cannot go to costume parties... you can have some blood fractions but not whole blood... you can't read any stuff that is against our opinion... yadda yadda yadda.
My mom (an active JW) argues that theses are not rules but only guidelines. Ok, that's more balanced, but the fact is most JWs view anything the WTS says as gospel.
I think it is human nature to want black and white rules to follow so that you can be more confident you're pleasing the big invisible man in the sky.