Why is asexuality not added to LGBT?

People aren't generally discriminated against for being asexual.

It has been. The letters include LGBTQIA (Lesbian, Gay, Bisexual, Transgender, Queer, Intersex, Asexual). Some also add "P" for "pansexual", but some conservatives have claimed it really stands for "pedosexual" which is not acceptable. So some lump pansexual as a subcategory of bisexual.

Asexual people have of course been around for centuries. Many women really aren't interested in sex at all. And in previous ages these women were considered virtuous for avoiding sex, and they would often disapprove of sex in others as well as themselves. Asexual Roman Catholics could become nuns (or monks or priests if they were male). Some asexual women married, but quickly managed to put a stop to any sex life in the marriage. And if an asexual man married, his wife really couldn't complain about the lack of sex without seeming like a "s-l-u-t".

Including "asexual" in the letters was a clever ploy by the sex-positive community to get these people on their side. Asexual people could say that they didn't like sex, and that there was nothing wrong with them, without having to couch it in moral terms and condemn others for their sexual choices.

Still many asexual people love to take the moral high ground and claim they are better than those who like sex. So some join conservative and/or religious groups and condemn sexuality as being immoral and ungodly.

And other asexual women join the sex-negative feminist movements, and they claim that no woman really likes sex with men. This is exemplified by Professor Catherine McKinnon's quote, "All sex, even consensual sex between a married couple, is an act of violence perpetrated against a woman."

For the same reason atheism is not listed as a religion

It is.

i'm pretty sure it generally is counted as lgbt? not as a letter in the acronym (unless we count the extended LGBTQIA+, but personally i dont think we need to expand the acronym itself), but just by definition of not being heterosexual

Asexuals have not had it as bad as

mny of the lgbt membrs & there are shades

of grey betwn all sexuality & gndrs.

When listing the shades of blue, why isn't Pink included?

Partially because people who identify as asexual can't come to a coherent consensus on what the Hell it means, as it stands right now a sexually active cis perisex straight person could identify as asexual on the basis that they "don't experience primary attraction" or whatever, that person is not LGBT.

Asexuality is a term that has really only come around within the last 10 years. The lgbt acronym has been around for decades. Aside from the asexual term, there are a whole slew of other new terms. If we added them all the acronym would probably be 50 characters long. Its better to keep a simple acronym that everyone understands.