With utterly vanilla, standard rules, yes.
You can have systems that are clearly instances of PD (or at least related enough that one would use the same term) where the payoff structure makes this not so clear.
Like, oh, defecting on a cooperator yields 100 points instead of the usual 5, and the other player gets -95. Then defection becomes profitable within 33 rounds of the end, not just 2.
Also, in uncertainty or accidental defections, and it ceases to be so crazy to defect. What if you play with two other players, and can see only the total number of defections and cooperations you faced? What if you aren't sure how many more moves there are left? What if there is a continuum from cooperation to defection?
Well, let's get back to reality. We were talking about the way normal people think, remember?
So consider a normal person. When, in the course of his typical life, does he have to make choices in a PD situation? At work? When he's drinking beer and watching the game with his buddies or when she's watching a show and gossiping with her girlfriends? When looking for a mate? In relationships with parents or kids?
PD is a neat construct and certainly occurs in real life -- rarely. But for your regular bloke or gal it's a non-issue and they don't spend time thinking in terms of a theoretical situation they don't care about.
I was reading reviews of HPMOR on Goodreads and I noticed that the people who didn't like the book were essentially "put off by the rationality". They thought Harry was arrogant and condescending.
Then I was thinking, a lot of people are "put off by rationality" for similar reasons. What a shame. There's a lot of value in spreading rationality, and this seems to be a big obstacle in doing so.
Any thoughts on how to make people less "put off by rationality"? I think the core issues are: