Heh, if I had to guess..

..(maybe not so wildly), I'd say that a person's sexual preference has nothing whatsoever to do with it. Rather, it is more likely to be a particular set of personality traits, which just happen to appear more frequently in most gay people but also many non-homosexual people too.. eg empathy, caring, social behaviour, other similar related traits - a way of ensuring that aggressive violent stupid people don't get control of awesome destructive power (like a smart gun that only works for the fingerprint of the owner). Possibly why (allegedly) so little progress has been made in 801-odd years in their studies of captured UFO's by the military, the sorts of people who usually have such a shortage of those kinds of empathy-related traits. My guess is that they could only get what they want by deceiving or coercing those who do.