Okay, despite not being an ENTP, I'm going to throw in my two pence worth, based on how it looks to one of your ENFP cousins. I know this might be annoying as the thread is "Ask an ENTP", not "Ask an ENFP to pontificate about ENTPs". so take my question as: how much of what I write rings true and how much is well wide of the mark?
I still see you guys as "people persons" though. A people person, IMO, is not defined by whether or not you can remember names and faces. People can get over it if you don't remember their name. You guys still have the ability to make new friends all day long. There's another thread going right now about how ENTP's need people around them to be productive. You guys enjoy people. I don't. I mean, I do to some extent. I like people. But, I really want to like them from a distance. Call me if you need something, and I'll call you if I need something. Be a part of my network and I'm willing to be a part of yours, but don't bother me too much. It sounds horrible. I care about people more than that, but you see my point. Compared to your INTP "little brothers", you have the "people" part of life so easy.
The ENTPs I know tend to be very gregarious and so need to be around other people, but they tend not to be great at relating to others on terms other than their own. They're good at making friends because people interest them, but that's not the same thing as being interested in those people being their friends. As a fellow ENP, I know how it can sometimes come as a bit of a surprise when you're just doing what comes naturally in the moment, then every once in a while, whoosh, out of nowhere someone will unload an emotional baggage on you. You're left thinking "whoah, how the fuck did that happen?"
To most people in general, friendship carries with it responsibility, and the flip side of easily being able to make friends is that you have to be adept at handling that responsibility. I think that's something that ENTPs find a struggle, and I think it's the reason why a lot of ENTPs will protest that they're not really people people. It's not that they're cold and heartless and that they don't take their responsibility seriously, it's just that it's something they find difficult.
Conversely, from my own experience of dealing with one ENTP in particular - my father - I've also found that when they do feel a strong emotion and affection for someone, they struggle to express it on terms other than their own. To avoid derailing this thread by delving into a set of complex personal issues, which in any case are rather boring, I'll give just one rather petty and superficial example. I absolutely hate it when my father puts his arm around me in public (fortunately he doesn't do it in private). Every time he does this I tense up and start slowly physically distancing myself from him so that he'll withdraw the arm. It should be obvious from my actions that I don't like it, yet he keeps doing it. It bugs the hell out of me.
Okay, on it's own that's is a pretty trivial example, and given that he's clearly unable to take the hint, part of the problem lies with me for not simply telling him to stop it. But the larger point is that in any kind of relationship people are going to carry with them certain needs, and as long as you can't decipher what the other person's needs are, you are going to end up running into a brick wall. For all their gregariousness, I think ENTPs probably spend more time running into walls than most.