To kick things off, in the interest of debate, I will state that I do not believe him to be guilty of being transphobic. I think that we have our own preferences on who we want to date. He didn't insult her for being trans, he didn't imply any hatred towards her for being trans, he merely said that he wouldn't date her knowing she was trans. That's acceptable right?
Myself, I'm a fairly open minded person, and accept everyone for who they are. That said I wouldn't want to date a trans woman, Why? Because I am a hetero male, I am attracted to women on a physical and emotional level, and just knowing that you were not physically a woman to begin life, I don't know how to explain it, it's not a disgust, it's just a lack of attraction.
I don't want to offend anyone with my views, but it's a subject that's becoming more prevalent within society and one I've been trying to understand. I don't want to be labelled as transphobic just because I lack an attraction to trans women. I mean, I've seen pictures of some that are physically stunning, but it's that underlying niggle, that knowing that they were once physically men that puts me off.