I find, that regardless of the edition and the amount of RP material within the books, you will always have the munchkins who are more concerned about stats, treasure, and gaining power. I found I hated 3.5 because of this issue. Balanced classes were not the concern of 3.5. There were dozens of class/race/feat combinations that could easily make one player a god, and the others feel completely useless. So the problem there wasn't the RP. It was being restricted of what you could play in order to make yourself stand out in the group.
I know, that one of the few things I ever wanted to play, was a gnomish artificer that I found in the 3.5 forgotten realms books. I loved the idea of being a tinkering mechanic who could make any kind of spell effect he wanted by using alchemical and mechanical devices. Sounded great from an rp perspective. Then I realized, that due to poor balancing, poor rule explanation, and poor overall thought into the class, while everyone was throwing fireballs I was shooting a melf's acid arrow at one guy a round.
Now, in 4.0, powers are very limited on the description for a reason. That reason is "let you fill in the blanks".
For example. If there is an archery power that says that it pushes back a creature two squares as long as well as damage you could say "I draw back my bow, speaking an arcane phrase as my arrow tip glows red with the power of my words. As the arrow strikes, a blast of fire throws it back into the wall behind it"
The problem with rules dictating how something looks or what it does is that it limits your imagination. You can't teach imagination to someone. They either get the idea or they are too "grown up" to want to. If you want people to get involved with the story and the RP elements of the game, then you just have to be a good DM. That's all.
