Because it was bad for the game. PL was a bandaid fix to a problem, but it's a cure that's worse than the disease.

We players will take the path of highest gain, even if it is as unfun as digging through a stone wall with our teeth. The number of people who participated in PL evidences this. In order to make a good game, the path of highest gain must also be fun.

Was anyone having fun sitting AFK soaking up EXP? Was anyone having fun running back and forth killing mobs 20 levels below them to "earn" the right to sit down as a lower level job and be PL'd by someone else while they watch a movie?

If the game isn't fun at the low levels, that's a problem that needs to be fixed. If doing the tutorial quests and their first batch of leves doesn't at least get players to the level where they can start doing the lowest tier of real content (10-15, if the new dungeon near Limsa counts), then that should be fixed.

I would be totally in favor of increasing the EXP from the starter quests to get people up to 15 in a day. I'd also be happy if I saw the EXP needed 15-40 reduced 30%. This would solve the problem that PL bandaided without forcing new players though a 15-hour hazing ritual that's worse than any part of the game.