Well, let’s face it. While it can be nice to meet new people, or old, and create groups to do a quest, it’s not the fastest way to level up.
But there are occasions, when grouping is your best choice.
You should only join in groups on special occasions like:
* when you are doing an instance at your level or above (not beneath)
* when two persons or more reach the spot where you have to kill somebody and get his head (or something like that)
In the latter case, the alternative to grouping is for some of you to wait to the boss respawns, and that would be a waste of time, and create problems, because the rest of the mobs will also respawn.
If you are doing a quest where it’s stated that you should do it in a group, you’ll do it faster alone, if you just wait a level or two more.
Doing a quest alone gives you much more XP for each kill, and you don’t have to quarrel about the loot.