It is a sin to be critical? Being critical is a bad as fagottry? Ok.
Very simply, there are lists of scripture where people do stuff that is worthy of death. Romans 1, 1 Cor.6, 1 Tim.1, Gal. 5:16ff. Please read these chapters very slowly.
The sin of homosexuality is included in those lists. But so is idolatry, rebellion against parents, drunkenness, thievery, and so forth.
Homosexuality is AMONG many sins that cause a person to be excluded from the kingdom of God. We err when we make it worse than other sins. It is a way for us to feel better than them, and that is hypocrisy.