I think OP is maybe saying it too bluntly, but I thought I might step in and offer a different perspective.

In a homophobic, heteronormative, ignorant(as in they lack knowledge on sexuality terms and what they mean), society, I think there are going to be people who identify as straight due to the aforementioned reasons. Would it be the majority of straight people? Perhaps not. But I know in my own experience, and a lot of people who figured out they are bi or gay, once they conquered the aforementioned problems in themselves, that's when they realized they are not in fact straight. I used to identify as straight as a teenager, despite having attractions to people regardless of gender. I wouldn't allow attractions to other people, besides what was viewed as heteronormative, be given a second thought.

How many currently self-identifying straight people would be doing a similar thing I was? I don't know and there's no way to measure that - but as I said in a comment, I wouldn't be surprised if it turned out to be the majority of people doing that.