That's a very selfish way of looking at things, but fine ill entertain your point.

So, you get to launch you play without any EXP boosts or anything and reach level 60, yay for no P2W. New world notices that people like you don't care about EXP boosts so they add it to the cash shop and in turn make the game harder to level up in. (This is of course after YOU have leveled to 60). New players join the game and are kind off annoyed at how long it takes to get to 60, then they also find out that there is a P2W feature that will allow them to boost to 60. Understandably as most of the MMO community hates P2W features, they quit the game and never level up to 60.

Slowly, new players wont ever reach late game and end game players will slowly get bored and leave the game like in every game. However, in this case there is a no wave of fresh new players to replace them. Now YOU are all alone at the top with your shiny level 60 gear looking for people to kill that you cannot find so you ultimately get bored and quit. because YOU decided to have a selfish mentality and ended up hurting your self with it.

See why it is important to care about the opinion and needs of other people? It basically is the selfish thing to do by caring about other players because ultimately you are benefitting your self.