There are 2 different cases of people being homoloveual.
1 - It's a choice. You might not like the idea or having love with woman/males depending on gender. Whatever, opinions do exist.
2 - Some studies show however that homoloveual men produce more estrogen, and women more testosterone. It can be a genetic thing, however this is all science, theories what have you.
Honestly, if someone attacked me just because of my loveuality, I wouldn't use it as an excuse, because I'd bop at them right back. I may be gay but that doesn't mean I'm not up for a fight.