Wow... this fight will be fought for eternity. It was fought in beta and it will be in the future, whether we get them or not. It's always a heated debate, a lot of people are very passionate about them, either way
I just want meters because they're fun. For me it's an extra minigame I enjoy:
"See how much I can push my little red bar to go up, while still paying attention to the mechanics of the fight".
I usually don't turn them on when learning a new fight, but when I know what I'm supposed to be doing and what I should and shouldn't be standing in, it gets a bit boring.
The little bars keep me entertained, and help push me to try and squeeze out just that little bit extra ^^ It's also a nice tool to help me figure out my rotations. Finally it also very simply adds a bit of oompf to the coolness of getting new gear. The bars go up further - I feel I got value for my drop. Since so much gear is customizable, my gear will look much the same now as it will later, so I'd like those little bars to help feel like my character is getting more pimped out.
I've rarely used them as an actual tool to decide who gets to raid with my group, it's only been a factor once or twice, and they probably would have been asked to leave anyway - simply for constantly Standing In The Fire™.