When you actually think about it, isn't watching nothing but cute anime girls arguably much more gay than insisting that watching a male vtuber immediately makes you a faggot?
Only being able to relate to cute anime girls is part of a beta male mindset. And as a coping mechanism for this, you immediately jump to the conclusion that watching a male vtuber would be some sort of attack on your own sexuality. That to me sounds like you have very little confidence in your own sexual orientation. If you genuinely believe that a man is unable to watch a male entertainer without fantasising about getting assfucked, you may be subconsciously projecting your own repressed faggotry.