The number of levels is the only thing you read it seems, and not any of the changes to questing in those zones.
As usual someone who can see only what they want to see, and is wilfully ignorant of the rest.
I'm afraid I can't agree with you, OP. I find questing and leveling far more satisfying than making a b-line to endgame right after release, only to end up complaining that it's too repetitive and that there's nothing to do.
Having to do 5 levels is a nightmare, 8 hours of life wasted every time. No1 cares about the quest chains, no1 needs 16 hours of practice learning how to use the new talents/whatever. Jesus, this is gonna be horrible...double the grinding time for 1 new tier of skills.
You should probably read some more. They said that it won't be a grind, but that it'll be fun and fast.
People like you are the reason for the many stupid complaints. Maybe there are people who like leveling and seeing the world not just raid this, raid that. You finish whole content in a few days without sleep, and then come and cry that there is nothing to do in wow.