Exclusionist

[Sarah]

One who would exclude another from some right or privilege;esp., one of the anti-popish politicians of the time of Charles

[Sarah]

A lifestyle of exclusion. Someone who is exclusionist is vegan, straightedge, and celibate, among others.

[Justin Bieber]

An [exclusionist] is someone who believes that [cishet](both cis and hetero) asexual and aromantic people are not LGBT, due to the fact that they do not experience same gender attraction and are cis.
The LGBT community is a community where those who experience transphobia, nbphobia and homophobia fight systemic oppression and bad public perception, neither of which cishet aces, cishet [aros], or cis aroaces experience.

[Sarah]

Acting to shut out or bar someone from a place, group, or privilege.