Your statement seems to imply that the loudest, and most controversial, members make it terrible for EVERYONE inside the community.
That is not the case in 4chan. There are a large number, if not a majority, of boards which have healthy, constructive cultures and are extremely helpful for hobbyists and enthusiasts.
So, if it's not terrible for everyone, then it's not a problem---as long as it's not terrible for you. Maybe, perhaps, this would work if the terrible people kept to themselves, but this is rarely the case. I was a regular poster on /mu/ for several years, but once the /pol/ users started trashing the board up, it's been a shell of its former self. And, again, that's just within 4chan. The worst things are what 4chan's community have done outside of the site. See also: GamerGate.
That is not the case in 4chan. There are a large number, if not a majority, of boards which have healthy, constructive cultures and are extremely helpful for hobbyists and enthusiasts.