As for WoW and watching movies. Just because you are button mashing doesn't mean you are paying attention to it. When I was playing my paladin I was basically autoattacking and hitting 4-6 keys depending on what I was fighting. It doesn't change. I often found myself watching anime on the second screen while killing stuff because all you are doing is hitting a key every 3-10 seconds to activate a power with a 0.5-1 second animation. Those spare few seconds inbetween can be killer when grinding a hundred of the same enemy. And this is the same for most MMOs. Always best to have something to distract you.
lol, ret pally rotation. Oh wait, faceroll and press 3 buttons if they come off of cooldown with no chance to fuck up.

Missing a few seconds won't do much for a ret pally.
You could just make a single key macro to spam all three attacks in a priority, set it to mouse scroll and watch a movie.
Trying to fix my rotation (static dk rotation with no room for error), watching stacks of a ticking debuff, watching my runes, telling what my ghoul to attack, calling out things over a mic, and moving away from people who are blowing up every 15 seconds is fun to multi-task.
The only time I ever payed 100% attention in WoW was PvP and raiding and thats only because they were the 2 best parts about WoW as almost any game for me anyway.
Well, someone didn't pay "100%" attention during our Sindragosa Hard Mode 25 attempt, caused this... The whole raid was ice blocked, except for two people, including me.