I personally don't think S's as a whole are scatter-brains or less intellectual, but that they use their intellect in different ways. You, for instance, are street smart, and many istp's admire those qualities in people. It all comes down to what a person sees as being important to their own success. I, for instance, am very irritated by people who can't change or alter their opinions or ideas easily, people who do the same things day-in-and-day-out, no matter what new information is thrown at them. I've realized this is a real problem for me, so I'm on my way to changing it. I think it's because I see that the ability to change rather quickly has always been integral to my success at anything I set out to do. So others who can't do it, well, in the past I have thought of them as stupid, but I realize now that they were just different, that although I could see where improvements would change their lives for the better, they were content to remain in the position they were in forever. I realize that a lot of people view "holes" in my way, and that many also think that because of them, I am stupid. (I can't imagine any estp thinking the wwf is real, although I suppose stranger things have happened lol).
Some of us can show commitment to certain things when we need or want them badly enough, it is just done on a day-to-day basis and it takes some work (Michael Jordan, for instance, showed undying commitment, although he acted very non-committal about certain things). Me, I've been in a relationship for 7 years and never cheated a day, mainly because I realized at some point that cheap sex was not worth hurting someone else and crumbling something very important to me. Many times I act more non-committal than I am in reality, because I need to create space..... Promiscuity can be fun, when it works out. I've usually been disappointed by it honestly, because it was always a lot better in my head than it was in action. Sorry, but I've been known to revel in those things in the past lol..... uncultured brute, I would tend to agree with that in some ways for me, but certainly not all. I think my point is that I'm pretty happy with the stereotypes. I accept them, and I've learned to grow within them. All in all, yes, we are all born with certain tendencies, but many of us learn to manage them well and to change them. Being non-committal is one thing I generally am, but that doesn't mean I can't ever show commitment.
ISTP's have a way of being able to understand complexities, but that doesn't mean that they communicate with others in that way. I think that is misunderstood, because we can be poor at verbal skills and communication. Many times also, we just like to observe others and not take part in it. We are also very private and like to keep much of what we think, to ourselves. And if it looks like a duck, and it acts like a duck, it must be a duck.......many people, including me many times, fail to see what's under the covers.
So anyways, I expect that certain people will view me in certain negative ways, but I really don't give a rat's a**...... LoL, and I will like them regardless of how they view me. I refuse to allow the prejudices and limitations of others to control me or what I think about them.
I find that I also tend to stereotype according to type, but I think it's because I really am pretty new to mbti and don't even know what all of the stereotypes are yet. I generally do know that many people can manage their tendencies well and to even act against them when needed. I think the more I observe and study the types, a better and more complex picture will emerge.