What are you even on about?

There is no "entity in charge" of the LGBT acronym, no central authority approving, adding or removing letters, or any particular concern over "alienation" from adding or removing letters. It's a cultural idiom, not an ISO standard.

Regarding its "nebulous" nature and "motives," quoting from Wikipedia[0]:

    The initialism, as well as some of its common variants, have been adopted 
    into the mainstream as an umbrella term for use when labeling topics 
    pertaining to sexuality and gender identity.

    The initialism LGBT is intended to emphasize a diversity of sexuality and 
    gender identity-based cultures.

Note that, while the quote mentions "LGBT" specifically that description also applies to the "common variants" also described, including LGBTQ, LGBTQIA, and others mentioned elsewhere in the article. I only point that out because one of your flagged comments mentions how alienated and confused you are by "the whole gay thing," so I wanted to be as clear as possible.

And if you're instead talking about the registrar, they're not a mysterious entity, and their motives are clearly spelled out on their policy page[1].

[0]https://en.wikipedia.org/wiki/LGBT

[1]https://toplevel.design/policy