It depends on whether people mean a system like TESO's, or one like WoW's, where you have a spec system to customise your class to a degree. I wouldn't like to see TESO's, either, since I don't like that game's class design approach, but I liked the WoW spec system. Granted it's true that in end game content theorycrafting does result in specific builds being preferred/required for end-game raiding content, but I still like the flexibility for other content.