Just to be clear from my end, I take role playing to be the entire enterprise wherein we play with stuff that exists solely in our own minds. Role playing can also mean portraying a fictional personality, but confusing the two can make it harder to communicate.
A lot of play I've been a part of is 1-on-1 Player to DM turn taking. This is especially prevalent in combat or whenever in-game time slows down. I see this like swapping off turns with a console's game controller while everyone else watches and waits. To me that directly leads to boring play and is poor design, but... I would not remove it from the game altogether. I would simply make it an option. (Perhaps in terms of design boring, slow play could be its own detriment?)
When the locus of a game is moved from the corner of the room where the DM sits to the center of the table surrounded by the players, then everyone is in place to engage as they desire and the DM is afforded the opportunity to hang back and referee - watch, listen, and quickly relay judgement calls and results.
I enable optional group or grouping of initiative, even advocate it at times, while suggesting the strategic use of a Caller whenever the players become really confused. Neither technique is mandatory, but neither are they automatically "against the rules". I use them because they are designs which routinely lead to more enjoyable play.
