I can't vouch for every one of Blizzard's hojillion World of Warcraft servers, but at least on the server I play on, not a day seems to go by without a public channel exploding into a redundant debate about skill vs. gearscore.
For those who don't play WoW, or don't play WoW at the endgame yet where gearscore is a consideration, the short version is that that there are formulas that summarize the gear you're wearing into a simple numerical statistic. The better your gear the higher your gearscore.
Obviously there are people who don't appreciate having their worth as a player distilled down into a make it or break it number based on the gear they've managed to collect. And that's valid. I know that I've seen people with less-than-stellar gear pull some very impressive performance out of their equipment simply by knowing their class and their rotations. And likewise, I've seen some incredibly geared individuals come in and fumble around like a drunk turnip. So hands down, when faced with the choice between a skilled player with so-so gear and an intoxicated vegetable with incredible gear, you choose skill. Skill over gearscore.
However, when you don't know your two choices from a hole in the wall, it often helps to have some sort of yardstick by which to measure your options, and that's where gearscore comes in. Looking at two players that you know nothing about, you tend to opt for the one with the better gear, because you'd like to assume that in order to get the better gear, said player has had more experience or skill. It's not foolproof, obviously, but when you have nothing else to go on, you could do worse.
Unfortunately it has transcended being a simple tool, and taken on a little bit of an ugly life of its own. Let's face it, gear in MMO's has always been a status symbol. You see that dude walking through town with his massive glowing sword, and you know he's downed some cool shit. But the introduction of gearscore has turned it into a readily and easily quantifiable commodity. It's the new "You must be this tall to ride" sign staked out in front of raid instances, and it's the new standard by which players judge other players.
Perhaps I'm just waxing nostalgic for a time in MMOs where everything wasn't reduced to numbers, even a player's overall "uberness". When there was still a little bit of mystery involved, and not spreadsheet upon spreadsheet of data.