I don't recall anyone who has said powerleveling should absolutely, positively, not exist. The idea is that one group wants powerleveling and couldn't care possibly less if the content exists and the rest of the community is happy, and the other group wants multiple ways to be viable at honestly no cost to anyone.
Considering how many people are happily powerleveling, I think the concern is when you're running into problems avoiding it.
As far as being lonely at the top goes, I can't imagine a more wonderful opportunity to make friends in the game to play with later than to help those lower level players find those new ways to level. It's not always about reaching the cap. The concept of being a veteran in an MMO seems lost these days.
Once the game starts costing money I think the amount of people wanting a mediocre experience in content will drop. I REALLY hate to say it, but it's obvious most people who have played FFXIV during this time were here for the graphics and free play, not out of loyalty or interest. There are lots of fun MMOs out there, and if you're playing an MMO for a story/content, you don't skip it. It's just not logical.
I'm not going to argue with your point - it is valid - but you have to understand how incredibly stubborn and devoted the secondary group is. The former group may bring in the cash, but the latter is where you will be gauranteed to keep recieving that cash. The trick isn't to absolutely, under any circumstance, please the first group only, but to trick you guys into throwing money at the game to keep funds up (Through patches that promise a better game - like how WoW does, and any of us who like WoW know how potent this is) while the more reliable, stubborn group plants down and stays under even the most harsh of circumstances - that is, once you prove, as a company, you care about us, too.
Of course I don't agree to those tactics, I'd rather us all be happy. Just don't forget, the finicky, attention-deficit players are much easier to manipulate and will always ebb and flow in and out of a game's community. S-E will never make this game better than FFXI, so they only have to please so many people. "So many people" stuck through with FFXI for years before WOTG and Abyssea, and FFXI will be seen as a successful MMO in the books of gaming history when it finally, fully, ends.
Hmm, which would explain why Yoshida mainly focuses on appealing to the non-loyal-FFXI potentials. How interesting.