If I had a child and I would die because of some thrilled-crazed fun-seeker e.g. in a car crash, I don't think I would have a problem with e.g. G.Westerwelle as foster carer or even Mr Ratzinger if he were younger, tho then again I probably wouldn't really know Mr Ratzinger's partner even if they were anyhow "married". Two dudes who arguably may have been sort of asocial because of sexual orientation, even less so. Not meaning that every hetero couple would be as from heaven itself, tho leaving aside such in my opinion exceptions such as mother picking up her small child with both hands while having a lit cigarette in her mouth or female being "so much in love" that she would murder for him, females seem to me as way more sane in many matters. Which is not meant sexist. I agree e.g. if a mother wouldn't have been always cleaning up for her boys then they would have been less likely to walk through life sort of expecting of everyone else to fill the "role" of their mother. Tho arguably sort of do with biology and history of species, females seem to be sort of more in touch with nature overally.
Anyhow, as far as adoptions are concerned, I think moreorless immediate family should have a role, such as that in the aforementioned example of me dying, the mother of the child is relevant, also grand-parents of the child, and uncles/aunts can be as well especially if a sort of family environment already with room for one more. These things of course depending on age of child and other things. E.g. a 16-years old about to finish school probably wouldn't really want even themselves to be moved across the country into a new school and basically different environment. In the case of that not being even an option or so, and assuming younger age of child, an overall environment where there are children would seem nice anyhow, albeit true that orphanage sounds rather sad long-term anyhow, and that not only because of the often tragic circumstances which bring children there, but also because of eventual friend relationships being often taken apart when a child and/or carer leaves to some other place away. So all in all, while I don't think that e.g. gayness makes a bad parent, I also don't think that "we want to adopt because we want to be a happy family we weren't when we were younger" is really putting interests of the child/ren at first place and that in cases it makes the impression of wanting to adopt "Mittel zum Zweck", which isn't a thing bound to sexual orientation per se, tho a gay couple seems to be lacking the biological predisposition to give birth to a child, which is why I am pointing it out regarding that even if a gay couple is sincere about providing stable home and care, without party-lifestye or so, it is usually a long-term commitment during which if especially both get carried away with something there probably wouldn't be care as would be overally expected. Of course, if a parent happens to have a child of theirs from previous relationship then that the adoption issue is a bit different one.
As for marriage of same-sex adult age couples, while I think I understand connected issues about medical and property issues (which often can be "by-passed" by wills afaik), other issues are wide-ranging in terms of that not every country on this planet has/had a system where every adult in productive age is/was employed as some may know from e.g. East Germany prior to 1989 A.D., nor is it considered everywhere normal for females to be capable of doing any job males do, not only because of body-build, but also because a girl who didn't do any sports and was moreorless bound to be at home didn't do sports etc. as it is. So, complete male-female equality in everything would make males being in even more advantageous position due to how it is. So, e.g. if I were mayor of a small city and had 100 social family flats I could make use of, I personally would appreciate if they could be allocated to help particularly young families (e.g. he employed, she pregnant, both cramped at their parents' flat) instead of "helping" openly and proud gays who even if facing eventual discrimination at work or seeking work and/or flat still seem a bit more capable of taking care of themselves regarding various issues than many a female seems to be.
Certainly complex issues, and while not meaning to support any sex-ist/-ual negative nor positive discrimination, the overall political-social focus overally is rather required in other issues than in whether it should be ensured by law that a friend of a childless friend can inherit his stuff after he dies, in my opinion. Which surely understandably one of many relevant things, but not really something that would seem as very urgent especially as most contractual things marriage contract provides seem to be legally achievable otherwise, and it seems that many enthusiastic aren't completly aware of all the things that come with it.
That said, not against voicement of opinion etc. Myself, I used the opportunity to voice my opinion as well. And I don't see a difference to someone's e.g. capability of working as teacher because of sexual orientation. Nevertheless, particularly abuse of marriage for ensuring "someone" resident rights is unfortunately already an issue as it is without widening the field, and as said, I think the main focus should be a bit elsewhere.