I heard an explanation once that I wish I could quote precisely; it went something like this: It's not the peculiar traits in and of themselves that determine autism, but rather whether the traits affect the person's life to an extreme (and usually negative) degree. For example, one of my traits is that I detest people touching me, unless they are my significant other or a very small child. I am not simply a "non-hugger". The discomfort it brings me is so intense that I once asked my mom if I could possibly have been sexually assaulted in my early years.
My social isolation is another example. I'm far beyond your typical introvert. You know how people facetiously look forward to death so they won't need to work or deal with aching joints, or mundane nonsense anymore? I'm like "I won't have to be around people anymore." It's very extreme.
So. Your experience with people who are high-functioning but seem healthy? If they are truly healthy as you say, then, yes, it could be possible that they are simply peculiar, but still neurotypical. The tricky part is whether they are doing a really good job of ACTING healthy. I can act "just peculiar" to a relatively high degree.
