"Fear is the first enemy of knowledge."

I'd say that motivations don't matter that much and are also quite wide-ranging. In the end, being afraid of fear is still being afraid and there are people who pursue enlightenment who are simply curious, or, as you describe, enjoy or feel like it.

"if reality itself is unchanged by my enlightenment then its accomplishment can only matter to me"

That's the whole point, isn't it? You are I and I am you. There's only one identical I. Therefore "it is personal,” indeed, and also “important in the grand scheme of things." Not only because there is only one identical I, but also because --

"If I fail I am in exactly the same position as the billions of humans who preceded me in time."

And you will be in the position where you do what the parasite tells you to do. Now multiply that with those billions.

Thus, it's not a question of "who is seeing through the eyes of the parasite," but a question of through whose eyes the parasite is looking, whom is it hijacking.