It's quite possible he has a non-standard conception of what marriage means. Heck I can't think of any episodes pee even scenes in Star Trek that touches on marriage in any way. I'd say it's possible that he sees it as it is: an institution born out of social structure, which is objectively unnecessary to life. Doesn't change whether he's good or bad because it's a subjective measurement.
Lol he didnt, he just cheated on every spouse he had and lied to them and felt bad about it in his 80s in his book