
Player interaction can be one of the most interesting aspects of the game. Especially if the interaction is between players that aren’t all that fond of one another in reality.

Roleplaying games give players the opportunity to use their imaginations to live fantastical lives through their characters. They get to be awe inspiring wizards who manipulate arcane powers. Fearsome warriors with no equal on the battlefield. Galactic renown space-fighter pilots with reflexes so quick you don’t see them move until they are gone. Some players aim a little closer to reality, and while they aren’t something normally pushed upon high school students by their guidance counselor, they aren’t quite as fantastical as the setting they are playing in. Things like: Cowboy, Dolphin Tamer, or (my favorite) MixMaster.

Sorry for being late on this one. Discreet math is sucking my will to live.
As a GM, you have to give your players choices. If you don’t, you are basically playing a very weird game of make-believe where you control your friends like some kind of real life action figure, only imaginary. If you can make sense of that last sentence, you are light years ahead of where I’m at right now.
Basically role-playing is about choices, and your character’s reactions to the choices they make, along with the reactions to the choices the other characters make. If the GM strips away the choices, there’s not much point in playing the game. Now the choices may not be optimal, make any sense, or doom your character either way, but there have to be choices.