At least in the context of Iran, I can say that a lot of it is due to an Iranian Trans acativst and revolutionary, corresponding with Khomeini consistently, and making the argument in favor of an Islamic interpretation of Trans identity, which would persuade him to adopt it as theological doctrine.

Her name was Maryam Khatoon Molkara.

This is actually true.

It seems that homosexuality and bisexuality are less accepted than "cross-dressing" or presenting as the "opposite gender."