Quote Originally Posted by Tsukino View Post
e·lit·ism
/ɪˈlitɪzəm, eɪˈli-/
noun
1. practice of or belief in rule by an elite.
2. consciousness of or pride in belonging to a select or favored group.

It means the idea that there is a group of people, an "elite class" that has either the natural aptitude or simply superior training/education, who should be the ones who rule/govern/etc. In MMOs it's used to refer to players who are at the "top" of the game due to either natural skill or practice, telling others what they should do within the game because they have reached the highest tiers of success/ability/whatever themselves. Like all popular terms on the Internet, past a certain point people just start applying it to anything and everything they don't like because it has a negative connotation.
The real difference comes from the type of person they are. If they feel the need to berate everyone who they feel is below them, and thinks that no one else should be allowed to join at their level, then those are the kinds of "elitist" players that no one likes. But there are players who are really good at the game, and understand/know how things work, and are quite humble about their status. Those are the kinds that people should aspire to be like.

It's not being an elite player that is bad; it's the attitude that some come with. And usually, that comes from those who almost despise players they feel are beneath them. And those are the ones which gave rise to the negative connotation.

A good player (or players), who really can be proud to consider themselves elite, deserves the title and the respect that (should) come with it.