The film is set in the 1960's which is something I didn't know until recently. Societal opposition to homosexuality would be even more pronounced in that context.
We both know such marriages have happened and continue to happen and will continue to happen. Why oppose their open and exclusive homosexuality, while attacking their sham with these wives? Your position boils down to one calling for either compulsory reeducation or eradication of homosexuals. That's completely untenable.
You're quite right. When I studied Shakespeare years ago his respect for "the natural order" of things became clear. When the uncle murdered Hamlet's father to become King, then married Hamlet's mother, it was an overwhelming violation of the natural order. It inexorably culminated in a bloody massacre in the last scene. Society has approved of that view for thousands of years.
We are now dangerously close to legislating a 'politically correct' society in which all human cultural survival lessons learned over thousands of years will be trashed. We should tolerate homosexuals and respect their contributions, yes, but their sexual interests are a violation of the natural order of human procreation. What the queers call 'homophobia' is simply a psychological mechanism that gurantees survival of the human race.
Where can this stuff lead? It reminds me of Tom Lehrer's song "Oedipus Rex" and where excessive love for one's mother can end up:
"From the Bible to the popular song,
There's one theme that we find right along,
Of all ideals they hail as good,
The most sublime is motherhood
There was a man, oh, who it seems,
Once carried this ideal to extremes,
He loved his mother and she loved him,
And yet his story is rather grim.
We all know how that little exercies in mother-love ended up!