There is a natural cycle... (which can be prevented with a proactive approach)
Usually, early adopters/majority are highly engaged and interested in in-depth knowledge/understanding. And doing this with intellectual honesty and respect...
Then comes the rest... which usually prefers superficial understanding and easy mindless recipes.
And probably that happened in part to RPF, people with shallow/reductionist minds and a lack of systemic/holistic/dialectical understanding started to be the majority...
It also includes the commercialization of the forum... (as others already pointed out)