Language just wasn't what interested him. I don't know if that was a deliberate avoidance of any association with Tolkien, or just a fall out of the fact that he wasn't into languages himself and he was far more interested in archetypes and prophecies as the themes he wanted to play with in those stories.

The broad sweeping stereotypes get annoying, but they are in their own way realistic. The whole "money obsessed Tolnedran" and "sly Drasnian" thing isn't that far off of "snooty French" or "repressed English". Though he keeps his characters far more true to their stereotypes than people in the real world are.