The article 377 has been amended and of course the hardcore christian will have some worries concerning this, particularly because the Bible has a negative stance about 'unnatural acts' . I agree that homosexuality is not in with the natural instincts. But lets say that it is one of nature's abberations. (But also it seems to be not a small population with the homosexual inclinations!)
Maybe I can clear my thought on this issue if I think on it a bit laterally.
If out of 10 kids a mother has one abnormal kid,(could be any thing..say mental retardation) would it be proper for the mother to expect that child to behave like the other 9 do? Abnormalities are a 'normal' phenomenon in nature. And the behavior that such a child shows is "natural". As long as the other nine are not affected in a negative manner, the abnormal child can and just has to be allowed to be his/her natural self, because it cannot be altered! And it cannot in any way be criminal to be born abnormal.
Thinking in parallel terms; sexual instincts are, I believe, inherent, and cannot be developed or influenced upon. As long as it is inherent, it is 'natural' though not 'normal' natural instinct.
P.S: Not criminalizing homosexuality means accepting it as an aberation rather than crime but allowing marriage would give a wrong message that homosexuality is a normal social behavior rather than an aberation. It is important not to celebrate an aberation of nature though we spare it any judgement specially because it could give the wrong message to influencable young minds.