Will anyone actually see this as a failure of the "Thiel Fellowship"?
As far as I'm aware, the #1 education startup was created by someone who was poorly versed in the "science" of education.
He seems to be improving things with science now, but that's a fairly recent thing.
If you're talking about Khan Academy, they're a non-profit not a startup.
Also, he had several funding offers from VC's, so your assertion about what VC's might fund is incorrect.
I think it's important, especially with startups, to look to the future rather than to sit around judging the present.
In the beginning, Microsoft were making a limited Altair BASIC that only appealed to a handful of hardcore geeks, but later they had a computer in every office and home. You don't get there if you try to solve the world in step 1.
Education is the worlds biggest problems and opportunities right behind healthcare. People risking everything to make the world a better place shouldn't be denigrated like this. Their failure means there is more for someone to learn from.
There are exceptions, of course.