An adult has had plenty of time to reflect on that and make an informed decision. If someone was brought up in a religious environment and has not in their entire life had a choice in the matter, they are in any conceivable circumstance still a child (or, I dunno, being held against their will in a bunker, probably without internet access). Perhaps those kids shouldn't be using the internet unsupervised — that's for their parents to deal with. It's not for the users of a platform like this to deal with.
Religion and sexuality are NOT comparable. Yes, both can be considered a component of one's identity, but one is an involuntary intrinsic aspect of their lived experience, and the other is a voluntary decision informed by external factors.