Hahaha, well, there is something to that. I think we're a little mistrustful of those who seem like they've always been able to waltz through life on the merits of their charms. I tend to like ENFPs, though.
My problem isn't so much that an ENFP would talk to me for an hour and then walk away and that be the end of it. I have no problems chitchatting with someone on a superficial, fun level to pass the time, if it's someone that's easy to talk to. Not a fan of smalltalk in general, but there are definitely times where I'll strike up a conversation with someone, and I have no expectations of them for going forward.
What I cannot, and WILL not do, no matter who gets mad at me, is open up and share intimate, personal things, or things that I consider private, just because someone wants to be entertained for an hour or two. I will just not bite, because if I did, I would feel violated. Keep it at fluff-level, and we'll be fine. Otherwise, you'll have to be a real friend in order to know more.