All three of your points here are actually quite flawed.
A. - There is still much nature vs nurture debate going on as there is no "gay" gene found yet.
B. - Many families want to have children of their own DNA, which isn't possible from same sex couples.
C. - A child can't just "be accepting". You teach a child to be accepting.
To continue C, there are ongoing studies of same-sex couple children vs hetero couple children right now as there is obviously a difference in how they are raised. I think both of the couples can raise their child well, but I'm pretty sure there is a benefit to raising a child with both a mother and a father. Genetically, humans and most other sexually reproductive animals have a mother and a father to guide them at least some of the way, depending on what animal that is. Thinking logically, there must be a lot of instinct in humans that lies on having a father and a mother both.
- - - Post Merge - - -
I'm sorry that your adoption will be defiant, but the myth that the world is overpopulated is very untrue. Also, the world is about to hit a point where the big population increase of the last few hundred years is about to slow down a lot.
http://www.slate.com/articles/techn...y_actually_start_declining_not_exploding.html
There are some places in China and Japan that are overpopulated but that does not mean the world itself is overpopulated.