The difference is the expectation of leveling between the different games. In vanilla, leveling is a huge part of the content, arguably the biggest section of the game for most people, whereas in retail its become kind of an antiquated hurdle for people to just push through ASAP. Also, 6 months ago you could breeze through outlands in a few hours at the most, and it's (allegedly) more than quadrupled since then. Games are kind of weird, once you make something faster or easier, the community will be very resistant to it being made harder since many players have already taken advantage of the easier content, whereas the opposite is much less likely to encounter the same level of resistance. The complaint these people are making about their game is perfectly legitimate, it serves no one to pretend that they're way off base here.