You are absolutely right Quinlad, it is based on nothing, other than a supposition.
My contention is, as all four couples managed to make it so far in the process, and therefore were all, presumably, vetted to the nth degree, why were the gay couple chosen over the three perfectly acceptable (we assume) heterosexual couples?
Unless we are made aware that the three heterosexual couples displayed something that wasn't quite right, such as being a bit lardy or enjoying the occasional cigarette (which I strongly suspect is not the case because they made it so far), then why choose the gay couple over the heterosexual couples?
I could, quite rigtly, be accused of falling into the post hoc ergo propter hoc trap as well (and we all know there are many on this site who do follow this 'logic'), but I just don't get it!
Let's assume. merely for the sake of the argument, that all four couples were equally qualified to care for these children - if we assume this, and it is merely an assumption, then why were the gay couple singled out as being more suitable for the children concerned than the three heterosexual couples?
You do see what I'm trying to (probably clumsily) say, don't you?
Unfortunately, I suspect the couple were chosen simply because they were gay - which insults them.