People are not “engineered” to be gay. It is most often the result of considerable abuse done upon the very young by their abusive parents/caretakers. “Engineering” would be the result of a “plan” to effect that result. “Gay” in humans is most typically a byproduct of some earlier generation victim perpetuating the abuse cycle.

Most often it is a male who perpetuates that abuse cycle, as women can react in other ways (s** work, promiscuity, etc.) where male victims of s***** abuse have few other alternatives than to perpetuate the cycle of abuse through future generations.

… or you can believe the part about the long-elusive “gay gene”.