I read the whole thing, and I think your parent does have a point. If you don't mind some criticism:
That was my first guess – my first guess was that the difference between a generalist and a dabbler was that the generalist had some overarching theme or purpose, while the dabbler did not.
That was pretty redundant, even as a part of your thought process, since you'd already told us that earlier on. Just telling us that you don't think an overarching theme was it would have sufficed. And following that:
I don’t think that’s the answer.
You just said that a couple of sentences back. What I'm trying to say is that, while showing us your thought process did illustrate how you arrived at your conclusion, an outline of your thought process would still have read better if you had tightened it up some. Showing us your thought process by literally repeating it verbatim might strike some readers as self-indulgent.
Other than that, good points. :)