It doesn’t matter whether you perceive asexual people to be LGBT+ or not, bullying, harassment, abuse and threats are never okay. They are never justifiable.
Hating asexual people for their asexuality (or constantly mocking asexuality as an orientation/identity) is prejudice. And prejudice is never justifiable.
Adding “tumblr” before the word “asexuals” in your posts about how much you hate asexual people doesn’t make it any less prejudice.
If you think the harassment, bullying or abuse of asexual people for their orientation is funny
(or memeworthy) you need to seriously reexamine your attitude before you get be listened to in discussions about asexual issues.