I think the idea of the Discord community is great and if I could keep up with lots of different servers going on at once I would join, but even with the few I have and running my own FC's server some things get totally lost and I get behind on conversations.
With that out of the way, in regards to the "controversy" over this: There have been various other threads started to alert people to various other Discord servers and yet hardly a whiff of "controversy" has existed over them. I think that's a fair indication that this type of server is not only needed but perhaps necessary.
The way I think of it is like this:
I may have 100 friends. That's awesome. But maybe 75% of those friends don't feel comfortable talking about dogs/don't understand why I like dogs/don't like dogs themselves. I find that I have to restrain myself from making comments about dogs, even off-handed ones such as "need to let the dog out" or "sorry, the dog was barking while my mic was on", for fear of maybe causing strife. Otherwise, they're great friends. They're not really "toxic" but just not as open as I'd like. Now say I found a Discord server or a linkshell where the members enjoy dogs. Why wouldn't I join it, to have others with similar views/interests? I can still have those 100 friends, but I now also have more friends with whom I can share that part, too. That's not isolating myself. That's joining parts of the community that line up with my interests.
As well, until there comes a day where you can't find any slurs or derogatory comments/insults thrown at someone based off sexuality, gender identity, religion, race, or political affiliation, (and note: just because you personally haven't seen it doesn't mean it doesn't exist and that other people don't have to deal with it) there will always be a need and a want for places for people to just be themselves.