LOTR was absolutely the most difficult adaptation--just consider the fact that it took 8 years to develop a workable screenplay, and that is an indication of how challenging the material was to adapt. Then add in the sheer scope of what had to be translated from text to screen, with visuals, other-worldly characters, and the depth and number of characters, and it really is no comparison. It should have been a shoo-in, but it wasn't because it was not part of mainstream Hollywood's idea of who should win a screenplay award.
Hmph! Stupid academy!
I will agree with you there!