I've been watching a few of the Is TDD Dead? talks on youtube, and one of the things that surprised me is Kent Beck seems to acknowledge that there are just some kinds of programs that aren't worth unit testing. For example, right here DHH says that Kent Beck is

... very happy to say "Well, TDD doesn't fit in this case, I'm just going to bail"

It's frustrating to me that Kent Beck seems to acknowledge this, but nobody asks him to elaborate on it or give concrete examples. I'd like to know the situations where Kent Beck thinks TDD is a bad fit. Nobody can read his mind or speak for him, but I'm hoping he's been transparent enough through his books/tweets/whatever for someone to be able to answer.

I'm not necessarily going to take what he says as gospel, but it would be useful to know that the times I've tried TDD and it just felt impossible/useless are situations that he would have bailed on it himself. Or, if it turned out he would have tested that code it'd suggest to me that I was approaching the process very wrong. I also think it would be enlightening to understand why he would bail on such projects.

My opinion on why this is not a duplicate of "When is it appropriate to not unit test?"

After skimming those answers I'm not satisfied. For example, look at UncleBob's answer. He doesn't even acknowledge that such a situation exists. I really think there's value in understanding Kent Beck's position, not just a general, "What's your opinion?" type of question. After all, he's the father of TDD.