What are you considering actual transphobic comments that get upvoted

"Trans people mutilate their bodies", "trans people are mentally ill", "trans people are disgusting" (mostly including a pic comparing an "ugly" trans person to a gorgeous biological male/female), generalizing trans people as bad and lots, LOTS others, that I can't remember from the top of my head.

In general, our movements have a difficult time with criticizing only the irrational views and toxic rhetoric that TRA's have, without being hateful towards all trans people. Remember that trans people make 0.3% of entire population, they physically couldn't be policing us the way TRA do. TRA =/= trans people. Some trans people can be the crazy activists we're talking about, but not all. Let's not target our potential allies who respect our boundaries just to spite few potential enemies, let's address the silly things that are said about us.

and why should that mean that no gay subreddit should be allowed to exist

In my opinion, that's no reason to shut down a subreddit. I think adults should grow up enough to have a mature discussion and skin thick enough to carry the burden of truth, wherever it lies. But realistically, no serious company will agree to be a platform for a hateful movement. Reddit is clearly leaning to the left, so they will obviously and actively seek for an excuse to ban a controversial community like ours.

I tried defending both of the subreddits I've mentioned after they were banned on Reddit, but AHS clowns had screenshots of actual transphobia with lots of upvotes from other users. Some of the upvotes were obviously coming from the AHS brigade, but the comments were send by actual users, not brigadiers. They were simply dumb enough to post this. And I refuse to go into delusion territory and defend something against the clear evidence.

how trans subreddits are allowed to exist despite brimming with homophobia, misogyny, racism, and rape culture

Just the way r/askgaybros and r/tumblrinaction are able to survive despite occasionally being some of these things. Trans subreddits have the occassional homophobia, misogyny or racism on their subreddits, but it's occassional, vast majority of posts is just... Jesus, I don't know, whatever the fuck they're discussing. Same goes for askgaybros. Trans posts are consitent as of lately, but the vast majority of focus is still "my straight friend crush" and "am I gay if I gave a blowjob?". They obviously hesitate to ban this kind of community, because banning a specific users making these posts is more reasonable than shutting down everything, where majority wasn't against their narrative.