Quest based leveling: Future problem?

[bobbygunz]

Yoshi-P has stated that there will be a variety of ways to level up. Why does everybody have such an "all-or-nothing" mentality about this game?

Actually, Yoshi said that mob-grinding would not be viable, and that there would be quest-based progression (which would be the ideal way to level). And this thread is just a concern that quest-based progression doesn't make sense unless there's repeatable or self-directed content.