There's a huge difference because all of you (in a general sense) have been playing the quest treadmill level game for over a decade now. It's now ingrained into your sense of "what I'm supposed to do". It hard for you to grasp anything different. By creating a different product where you're not A) constantly looking at an xp bar B) constantly searching for quests to grab, do, and turn in C) ignore everything around you and just work on efficiency because you're trained to ignore the quest line and work mechanically through everything; by creating something different you are changing player behavior.
By taking away what you typical concentrate on, it allows the (hopefully competent and good) developer to refocus your attention on something different. Story. Gameplay mechanics. Rewards. Puzzles. Exploration. There are examples of all of this gameplay out there already in many games. UO, Darkfall, EVE, TSW, a myriad of survival games, Minecraft etc.
Just because no major successful game has done it, doesn't mean it would work. Because it has worked. Do say it doesn't work well in an MMO is asinine because it already as in a lot of different places.
Ever play GW2? There was definitely a group of people who loved exploration, puzzles and all of that. Imagine a game where you do that without an xp bar hanging over your head? That xp bar is always the driving factor for a lot of player behavior. Even people who aren't racing levels or care about speed have said "Hey I can even level while exploring!" The key phrase there "I can even level". Take that out of the equation.
Anyway, call it semantics if you like, it is in a way I guess. But I think redirecting the expectations, behavior and routines of the player would be a pretty refreshing experience. But yes, these are all different methods of advancement, progression and power measurement.
I'll leave this subject alone with this statement: Go look at the people who now "love" SWTOR because you can level strictly through the story quests. They have effectively taken out the leveling process of an xp bar and replaced it with a narrative. They were told to ignore the xp bar and enjoy just the story. It's a highly enjoyable experience. Why not gauge player power, experience just based on progression in a Story and build your game around that? Just an example.
