The gay/lesbian question hits a nerve, and I'm not entirely sure Frank's answer makes sense to me yet. He spoke of the homosexual tendency being a thing latent inherently to adolescence, and that this often dissipates, and that if this impulse isn't handled with care it can create 'aberrant' gays, of which an example is the Baron.
This is several claims at once, and to date we surely don't have confirmation of any of this, although not a contradiction either. To be fair, I think we still know very little about this, and likely won't for some time until it isn't taboo to speak of such things in most universities. I'll be keeping my eyes and ears open over the years to see whether we come to learn things to confirm/disprove Frank's idea on this particular topic. I would have preferred he give a slightly more direct answer to the questioner, specifically about why the only example of a homosexual person in the Dune books is of the aberrant variety.