Even more to the point, if the quality of a rule is a function of the tastes of a given table or group of players, then the efforts of amateurs necessarily have a higher ceiling in how good they can be than the efforts of a professional, no matter how skilled. Because the professional must write a rule for an entire community, but an amateur can write a rule which is tuned to a specific group of 5 people.
This is more or less why I basically won't play in games where the DM isn't actively creating their own rules content. I know people who can do this well, and I'm somewhat willing to invest time into people who can't do it well yet in order to get them there, but I'm not willing to invest time into something that will never have a chance to be as good as custom stuff can be.