Why people enjoying playing games with the exact same ruleset over and over again is beyond me. Half the fun of playing a new crpg is seeing all the new stuff the devs created for that game. In any D&D crpg, you start it up already knowing about 90% of the games content already. You know, classes, races, spells, weapons, thac0/bab, AC etc and so forth. How many times can I choose magic missile and chromatic orb as my level 1 spells before I put a bullet in my head?
The only thing you don't "know" is probably the story (although if the devs are just adapting previously written modules then you even know that as well), and very few D&D crpgs have stories that are interesting enough to carry the game by themselves.
I have no problem with D&D as a tabletop gaming system, but I have problems with it as a crpg system and major problems with it being used over and over and over again as a crpg system,