Definitely conflict in this view between different gamers, but rarely I find between different gaming groups. Because of the social nature in which gaming groups are formed, most gaming groups have this role of DM/player firmly established, and only comes to the fore when players are joining established groups.
For me, it's a question of "final authority." Originally, DM's were called "referees," and I still see DM'ing in this light today. For expediency of play and fun, the DM's word needs to be final authority, which does not discount disagreement - it only discounts protracted disagreement during a session. Players may try to use rulebooks to argue points in their favor, but in the end, it hurts the fun and enjoyment of all other players concerned, INCLUDING the DM.
Outside of the session, the DM needs to be able to firmly set rulings and precedents for his campaign, if he is to design a coherent setting that he enjoys as much as the players do. The DM is not an iron-fisted dictator, whose position is set for life; every player has an equal opportunity to DM, and set their own rules and precedents. Those who take a turn at DM'ing I believe better appreciate the preparation, foresight, and management skills that being an effective DM needs, and are better able to help the Dm during the game.