It's the name that they're using that's the problem: 'Actual lesbians' -- this is totally misleading and should be a label for real lesbians only. If 'transbians' want a place with nothing but support, they should start a subreddit called 'Trans lesbians and friends'. This way they can be around people who agree with gender identity theory and can support them. If you're elbowing your way into a subreddit called 'Actual Lesbians' -- with all the political and historical connotations that names carries, you can expect to get a few nasty comments.

Unfortunately, whether cis or trans, you will never be able to get validation from everyone. That's why it's so important to develop an internal locus of control, so that you don't rely on external validation for your sense of self.