Bisexuality and homosexuality are common among "higher" animals, such as dolphins and bonobos.
You can easily google it.
I've read some good scientific arguments for effeminate male behavior also being biologically influenced, seems to have to do with male hormone fluctuations during pregancy that affect the fetus's brain.
Nothing is 100% genetically hard wired, but there's significant evidence for sexual attraction and gender oriented behavior, which is a "brain thing" being heavily biologically influenced.
It's not condemned in the Bible either, so I figure the main reason people are annoyed or hate it is just plain old bigoted social conditioning. You see or feel your parents nervous and fearful about something and you take it on unquestioning as a child, and the cycle perpetutates.
The only way to break it is to experience that your fears are unfounded.
In other words, go out and mingle with some nice queers and you'll get over it soon enough.
There are probably people of all orientations who are TMI about their sex lives, just shut up already. It embarrasses me to see any couple making out in a frenzy of passion in public...get a room! Kissing, handholding and flirtatious conversation is normal between couples and doesn't distract me.
But, if hetero flirting and PDA is fine with you but the queers better shut up about it and keep their hands to themselves, then that's just your discomfort with homosexuality coming to the fore.