While this is technically true I think one should be careful to insinuate that this is an underlying cause. I don't think most people would say the same about homosexuality for example. It's just a more elaborate way of saying "it's a phase".
Saying it's cultural influence doesn't mean it's just a phase. I'm sure most people have life long personality traits that came from cultural influences.
Moreover, even if being gay or trans is just the result of cultural influence doesn't mean we should respect it any less. That said, it's worth asking the question isn't it?
