Seriously, the book well is just as deep as the Web comic well, but they've barely scratched the surface. Eddings' books could be just as epic as LOTR, if they do it right, and more movies too.
A big issue is politics. A book like Monster Hunters International by Larry Corriea would be cool, but it's written from a conservative slant most Hollywood liberals can't make work. They're not even digging into people like Asimov, who were more liberal.
On the other hand as I mentioned, Netflix is breaking things. There are a LOT of new things going on on there, and it seems to be easier to sell something to them. Spin off a parallel story for something like Schlock or Girl Genius, or take a series like The Belgariad and make a series out of it. You have enough space to fit stuff in, and do it right.