Maybe they can't tell themselves that, let alone a spouse. I think a lot of people delude themselves that they can change when they get married. I've seen smokers do it, drinkers do it, trans people do it, and I'm sure crossdressers do too. If it's a part of yourself that you are, at the time, ashamed of, you might think that getting married to this wonderful person will change that about you.
What people don't realize when they do that is that they won't hold their spouse on a pedestal forever. At some time, you're going to have to connect the real you to the real them if there's a hope of it lasting.
Dennis