This is something that a lot of MMO's keep doing wrong in my opinion. When participating in group questing, it's not uncalled for when the entire nearby group gets credit for killing 'X' mobs as a part of a quest. Why is it that credit for collecting 'X' items isn't shared amongst the party members?

The main reason I think this is an issue is because it really messes with the value of a group during questing. I've got friends I like to quest with and having to wait for or be waited on to finish gathering the rest of item 'X' before we move on is just a detriment to the fun of being in a group.