I personally think a lot of homosexuality is due to immaturity. This kind of person is usually childish in other ways as well. I think these usually outgrow it, but shouldn't be rushed.
Another major reason for it, which is common in the Tower, is the lack of opportunity to meet the opposite sex. This also happens in the military, where there are fewer rules against it (which is why it is more open there). Our society tends to set certain people aside and keep them from meeting the opposite sex, and that should be outright banned. Using this kind of force to make a naturally straight person turn gay should not be tolerated. Notably, the Watchtower Society does this all the time.
And then there are those who are gay because of genetics or from having their hormones messed up when they were little. Many of the poisons put in today's food, pesticides, phthalates from plastic, and pollutants are to blame for this. Notably, there are many prescription drugs that can have this effect and it isn't noticed. In cases where the problem can be prevented, it should since homosexuality is but one of the effects. (Many of the same substances will ruin the liver). However, if it has passed that point, or if the condition is genetic, no effort should be made to "cure" the homosexuality. If the person can have any poisons cleansed, general health might be improved and there is a chance that the homosexuality will change. However, in general, it will not and there is little that can be done to make the person naturally straight.
Forcing naturally straight people to go gay is wrong, whether by force or by cutting off the opposite sex. It is also wrong to force naturally gay people to go straight, regardless of whether it is genetic or due to those poisons that are too common in our environment. In the latter case, by all means cleanse the poisons out for improvement in general health. However, there is a very good chance that such a person will remain naturally gay and that should be their freedom.
One thing I do think: For gay people to force naturally straight people to do gay sex is bad.