I think "diverse" is actually an understatement.
Star Trek is well over 750 "hours" of live-action entertainment spanned across over 50 years. Plus books, comics, fanzines, fan films, etc etc etc.
There's something to appeal to everyone in there. A lot of fans only like certain elements of the franchise (passionately in fact) and then utterly despise other elements of the franchise (also passionately). They can be very binary. There are fans who believe that the "vision" of humanity's future that is portrayed is virtually a religious template...while others just want outer-space action adventure. Some only care about very VERY specific elements (Section 31 people are a great example...or Data fans, yikes).
Most are pretty normal and welcoming. Some are very kind and generous. Some are completely snobbish and mean-spirited. Some are downright awful. Then there's everything in between. Unfortunately, most places on the interwebs highlight the less-desirable elements of fandom considerably. The fans I know in real life are nothing like a lot of people you see writing comments on message boards and in comment sections online.
Like I said, just like any other highly diverse group that has had 50 years and 3 generations to develop.