Simple. Because sports have no bearing on the reproduction and whether a child should be raised with one of each sex or can be raised with both of one sex.
However, I don't really draw the line at anything. I am flexible as I learn and grow and I hope to always remain that way. With that said, my current stance is we are created in a manner that to me is obvious that a man is meant for a woman and vice versa for reproductive and family purposes as a child spends the first quarter of their lives growing and learning from their parents. Yes the mind has evolved and created the ability to cut corners in many facets of life. Doesn't mean it was the best for us as individuals or a society. Do I think Homosexuality will take over the world? NO. Do I believe homosexuals should be able to live as everyone else? Yes. Do I agree that science creating the ability to manipulate genes and provide an unnatural evolution or expedition is a good thing for the human race? no. Do I think its a bad thing? No. Do I think its debatable? Hell Yes I do. Why? Because in our current physical form, to me, it (again) seems obvious how we were meant to come together for reproductive purposes.
I do have a conflict on whether a gay couple should be allowed to raise a child. Only because a part of me feels like it isn't right to deprive a child both sexes as a role model and mentor. Would I ever vote to take this right away? Hell no. Because I understand that my opinion is just that. My opinion. Its not based on facts, Its based on how I perceive the best opportunity for a child to be raised is and that's with a parent from each side. With that said, I know a couple and fully believe the two of them would be able to raise a child and provide and nurture and love that child every built as much as a couple of opposite sex would.
I guess, I just keep getting hung up on the fact that the child was not created by the parents and thus, it doesn't seem natural. I don't feel or believe this based on any type of religious background or upbringing, for I had none. I was raised by divorced parents moving back and forth from one to the other, but mostly by my mother. Please don't crucify me for my opinion, as I have also tried to make it clear that I mean no harm or disrespect to anyone and am not trying to judge or belittle anyone.