Well, I'm comfortable being female. I have issues in that general neighborhood, but just living in the body I've got is fine with me. If there was a cheap, safe, reversible way of becoming male, I'd try it to see whether that was just as good but different, but that's neophilia rather than gender issues.
When I heard about what people go through with gender dysphoria, it took very brief thought to realize if one's sex was somehow cross-grained to one's temperament/spirit/texture of life, it would be an utterly miserable thing, and it's excellent that sex change hormones and operations are available.
What I'm wondering is whether low-grade gender dysphoria is really common-- something much less than what drives people to sex changes, but which leaves people feeling that if they're enduring pain, no one else should be allowed to make drastic changes to feel good.
This is not intended as a complete explanation of transphobia, just wondering about a possible piece of it.
Addendum:: I certainly wasn't thinking that low intensity gender dysphoria would always lead to transphobia, but I want to state clearly that I absolutely think people can have low grade gender dysphoria without being transphobic.