Let me be more explicit: In you hypotheticals, reproductive technology is not available. But in the real world, it is! Why can't gay people--in the real world--use this technology to have children of their own?
In your hyptheticals there are no children without homes. But in the real world, there are! Why can't gay people--in the real world--adopt these children?
So because we have the technology we should allow them??
And as for adopting, you can't solve a problem by creating another problem. If you allow gay people to adopt kids, these kids will grow up in environments less ideal than that of a good heterosexual couple!!
These kids will be ridiculed all the time and they will face so much rejection and suffer psychological damage.
They will grow up with parents who don't complete each other. A kid needs both masculine and feminine nurturing. While a gay couple can try to provide that environment it will never be enough because they will simply retain the masculine/feminine part of their personality, whether it is the physical appearance, the voice, the interaction, etc... It would just confuse the hell out of the kid.
Instead of saying "Oh no, there are so many orphans!! We should give them to gay couples" we should concentrate on the reason why these kids became orphans in the first place. We need to educate people about the dangers of unsafe sex (especially teenagers), tell them to wait until they are a little more older and wiser. We should educate couples about the beauties of the having kids and raising them. It is sad that some people now prefer having dogs over kids!! We need to solve these problems, and we need to make the adoption process easier for people!! A lot of people are just overwhelmed by the whole process!!
Since I believe that being in a gay relationship leads to nowhere, why should we allow them to adopt children instead of fixing the problems that lead these kids being orphans??
You can't fix a problem by adding more problems