I can't speak for any other nerds, but I find it funny that you consider Adventures in Babysitting a good example of why Thor would be well known by the masses.
I find it more funny that you think that's what I actually said.
I cited that as an example of a "completely unknown" comic book hero appearing in a mainstream movie that had nothing to do with comics, without having any explanation needed as to who he was, what his origins were, or why a little girl would be obsessed with him. (Hint: It's because he's not, nor has he ever been for a good long while, as "completely unknown" as the desperate-to-be-special-for-reasons-no-sane-person-can-comprehend kiddies so deeply wish he was in order to make themselves feel elitist and special.)
On a slightly related topic, I also find it amusing when people assume their own ignorance is the same as the collective ignorance of the masses. I have a friend who, just a few months ago, had no idea who George Takei was. Oh, he's an avid Star Trek fan, could quote entire episodes if you let, but he had no idea who the actor playing Sulu was. When it was pointed out to him, he scoffed and claimed "nobody knows that" and adamantly stuck to his guns.
Kind of the same thing here.