I agree, 20% is ridiculous, but I think "rare" isn't an appropriate description. The best studies I can find on the topic center around 4-5% natural homosexual orientation.

That said, it's very dangerous to tell these kids they should be something they aren't, in either direction. The straight kids will snap out of it as they mature, I think, but there's no doubt that LGBTQ ideology (not gays - the radical ideology) is deeply dangerous.