The problem of people being power leveled in a week is more an issue with the game mechanics.
Without being able to effeciently level link anymore (I think, anyway) I would honestly feel sorry for anyone logging into game and having to grind out 50 levels for each battle class.

In XI, XP parties were a social experience. They were fun, at least for the first few hours depending on the party. You could build an incredible party and still be able to chat with people, get to know people, joke around in linkshell chat, all the while racking up XP chains and progressing through XP areas.

In this game, leveling up a job in an XP party is just mentally taxing. It's not as bad as it was before auto attack was added, but I can recall being mentally drained after only twenty minutes. I didn't enjoy myself at all.
And without voice chat, it's virtually impossible to socialize while in a party.

It's not an "experience" - it's a miserable grind, at least it was back when I had to do it in between Dunesfolk for Dinners.
If the XP system isn't changed I pity new players and can hardly blame them for wanting to be level boosted through shallow and uninteresting zones, past mobs with no character.

If you want to see an end come to the power leveler you should also (and firstly) call for a radical change to the way parties gain experience points.