I'm pretty sure we all know by now that RPGs all have a grinding aspect to them. Personally I think the most successful ones found ways to disguise it. Some games did it through pacing things in such a way that you never felt you had to stop and run around in circles to be at the right level. Others do it by trying to provide an interesting story or set of objectives to go with it. I don't think this game can be successful with grinding parties as the only viable form of progression.

Besides if you look at many other MMOs there is always the option to group up and kill mobs to level. But there are other paths to advance that are offered and you will find most players taking those routes. That tells me enough right there.