Just what consequences would nature suffer if two people engage in an activity that is guaranteed to result in non-production? I suppose that if they were one of say ten people on the planet then you might have a point. In this environment, however, your point is completely lost. Much in the same way that certain foods were forbidden in a time when humans didn't know how to prepare it properly. At the time, the rule was helpful. Today? Not so much.
What good would it do to tell you when you'd just ignore them?
Nevertheless, they're still there and include but are not limited to the folllowing:
1) Lust becomes the supreme value in same-sex relationships. They don't care what God, their families or anyone else thinks of it, they just want to act on their lust
2) Same-sex relationships promote families where no one is related to each other
3) Same sex relationships only have
one gender as a role model for their children
4) Children in same-sex marriages don't know what a wife or husband is or does
5) Children in same-sex marriages don't know what a mother or father is or does
6) Children in same sex marriages are given permission to act on their lust, no matter what it is, as long as they find a partner who likes what they like. So it inhibits self-discipline and encourages acting out
7) Same-sex marriages encourage children to use others as objects of their sexual desires rather than thinking about what's best for their partners
8) Same-sex marriages inhibits future populations
for starters. But again, those who don't care about the affects that same-sex relationships have on children won't see anything wrong with homosexuality since LUST is the highest value of those who support homosexuality. that's actually an adolescent maturity level that thinks with its hormones rather than its heart or brain.
The above doesn't even address the biblical and spiritual reasons against homosexuality which are
far too advanced for people who have no values higher than bodily gratification which is the highest level that animals are capable of. So I won't even get into them here.