For the sake of truth, it must be emphasized that in nature there are life forms that reproduce within the same sex. The human psyche is something far too complex to be fully described by science alone.
If we are talking about biological sex, you are right: it’s 0 and 1. However, if we want to talk about sexual orientation as it relates to mental health, that is a completely different story.
De gustibus non est disputandum... one's personal tastes and feelings are not up for debate. This was already discussed 2500 years ago; there's no need to trouble such giants today. Fortunately, we are all born different,otherwise, it would feel even more like living inside an Orwellian novel.