Agreed. OP didn't give much to go on, and the connotations around "dating" are a really significant factor in what we are discussing. It deals with the accepting or not accepting factor that is underlying the ongoing debate. If dating means sex, which sure as heck seems to be the case for majority of this thread, then how responses are positioned in the debate are going to greatly skew the perceived impressions of acceptance and/or bigotry involved.
I find the connotations for what it means to date to be too numerous. Even the related terms, i.e. 'romantic date' have their own ambiguity. If genitals are not being exposed / touched, then I think it can be hard to decipher the difference between a date and 'hanging out' or whatever it is people do when they are not dating. I like to think of a date as an activity of an enjoyment where two or more people will get together and share things, not the least of which is intimacy. But friends do this a lot. There are things that I would share, in terms of intimacy, with a best friend before I'd consider sharing it with a 'serious dating partner.' Some of things that I might share with a friend are possibly related to the dating partner and experience has shown that some of those things being shared can be deal breakers. Thus, it really seems to me a best friend is preferable to 'great dating partner' for many things about a (close) relationship, other than sexual relations. That can, quite obviously, get in the way of a really solid friendship. But I do think that best friends can go on dates together with the full expectation, mutual understanding that it will not result in sexual relations. And yet, then again, it might.
For me, I do assume sex is related to dating, but also think it is distinct activity from the actual date. Like if the people date, have sex, and literally sleep together, is the sleeping activity part of the date? Perhaps it is. Chances are if you are dating someone for a long period of time (let's say 10 years, and not engaged/married), that at some point you've literally slept together, besides engaged in sexual activity. But that would be one of those things that I don't think most (best) friends would have any issue doing, together.
So, we are assigning parameters to dating, and IMO overemphasizing the sexual activity, which does lead to the whole aversion of being with a transsexual person, or transphobic aspect of what's being discussed.
And because dating generally involves 'spending time with people' and in many cases involves spending lots of time in a great variety of ways, then it really seems to be a whole lot of intolerance being expressed to suggest one would not date a transgendered person because they have a penis. It actually strikes me as highly immature view on dating and yet, a practical consideration if the aversion is real and is strong enough that you never want to be put in the position where you think it could possibly come up.