i believe leveling is necessary for 2 reasons:
1. to give a sense of advancement(psychological)
2. to restrict player movement(game design)
to keep a player engaged in a game, we need to give them something to attain(max level) and a feeling they are achieving that goal(level increments). leveling is a simple way to get that.
to keep a player moving in a predetermined route(maybe so they dont get ahead of themselves in terms of storyline), we label certain zones as level 1-10, 11-20 and so on.
for the people who like levels:
how much level is too much? as expansions increase and level caps increase, it becomes a drag for new players to come in and level from 1 to say, 100 levels. what started out as a tool to measure advancement becomes a hindrance that a new player has to overcome. is there a better way to balance the need for increase in power for the existing player and the barrier of high level cap for a new player?
for the people who dislike levels:
now if we take away player levels, what else can we do to give players a sense of advancement? better gear? if all zones are the same "difficulty" then where is the challenge and sense of becoming more powerful as you play?
what other pros and cons do you see in the concept of player levels?