I think there are two things that go on here. One, there really are people who present themselves socially in such a way to seem compelling, or as you are putting it "complex". My best friend growing up is once such type. One of the reasons we stopped being such close friends is I perceived her socializing style to be inauthentic. She would bait people with a certain persona that created such wild (and inaccurate) perceptions of her. I know because, as her best friend, people would talk about her to me, and I'd be like, "Huh?" So, yes, there are people who purposefully do that.
Second, there are people who are just going about being themselves and other people are drawn to them, for some reason according their own criteria, not according to some general principle. Sure, some people's criteria might seem complete shit to you or me, but it's them making these connections and the people targeted should not be held liable as if they had been trying to attract that attention.
But I can see where the bitterness comes in. As someone who is shy and more reserved, I constantly feel irritated that I face a life of being ignored unless I learn how to throw out cheap signals to others, like, "Look at me! I'm so interesting!" But really how can I blame them if I sit around being quiet, why should I expect anyone to just magically find me interesting. You can stave off the bitterness at others by realizing that they are just socializing normally. I would suggest reflecting on the part you play in all of it and how you attract (or detract) others. If you aren't an inherently dull person, which I don't think you are, what is it? Don't know the details of your particular situation, but just sharing that this is something that I've been working on.