Simple question:
Two couples waited till they get married to have sex. Got married and had a healthy sex life till their death. No kids.
One couple is heterosexual and another couple is homosexual.
Do you have a problem with either of those couples? Do you believe that we, the public, "suffer" any consequences as a result of either couple's actions?
Lets take a look at the bolded part for a second, if we may.
In order to objectively determine if the public suffers from homosexuality or homosexual couples you first have to determine, or attempt to determine, what the effect on society is.
While I have heard a lot of opinions the closest thing I have heard of to a study goes all the way back to Kinsey whose study seemed to indicate (as I recall) that most straight people have had homosexual experiences and that most homosexuals have had straight experiences. If it did not effect society then it is hard to imagine it would seriously impact society today.
As a social experiment certain (But by no means ALL) Greek city states practiced homosexuality as a rite of passage for its youth. Lesbianism is not mentioned when discussing this but it would be difficult to believe it was an unknown practice.
It did not seem to effect marriage as all the men were married, even those who much preferred their male lovers.
Its one social consequence seemed to be that its army was self sufficient sexually.
BTW it did not seem to impede their militaries ability to rape and pillage at will just like the non homosexual macho men of the day.
The one social consequence everyone seems to agree upon is that fewer children might be born if homosexuality is allowed to happen unhampered.
Pardon me but humanity is in no danger of extinction if a few less children are born. In fact the opposite might be true.
So in the absence of a definitive study on the impact of homosexuality/lesbianism on modern society this is the best we can objectively do.
No downsides, no upsides.
It simply is.