Blizzard doesn't understand personal progression. SE is starting to head down the same path.
The Blizzard team never understood RPGs. They only had Diablo which is barely an RPG, more like Gauntlet with gear and a few story elements. They just had a good interface which was from there experience with RTSs. As RTSs go they were not nearly as good as Westwood, in the gameplay department and their interface design was already standard in the genre (colorful buttons that make everything clear). The RPG elements that made early wow pretty good were just lifted from other RPGs. But since the team didn't really understand why they were important the game quickly degraded. I remember comments from them like "that's just and RPG element" as reasons for removing them.