Rebuttals to the trite responses to tagging stance:
"X game does it and its not antisocial..." Okay, let's say you see x paladin in quest area, cool, you quest together. Once the quest is over, no words are exchanged, nothing social actually happens. It may seem like a small thing, but asking to group may result in chit chat while killing stuff and may result in friend listing, guild inviting. If this isn't happening, either you are a toxic person or they are, not the community as a whole. Open tag doesn't reward you for socializing.
"X game splits quest credit..." Okay, cool so that lock dotting and running around the field gets the same credit you get without as much effort. You play a class without an instant cast spammable dot. These same locks would /roll their eyes and tell you to re-roll. Other players seem like a nuisance for efficiency.
"X game splits kill experience..." So, by the time you run out of quests in one zone without reaching the level requirements of the next zone, you are stuck mindlessly grinding the few non-quest-related mobs away from other players. Seems like antisocial behavior. Other players seem like a nuisance for efficiency. "but you can group up..." Yeah, just like in wow... during quests.
Bosses and named mobs are always open tap, and the rarer multiples-needed quest kills always have their spawn rates increased or get put on dynamic spawn timers based on other players in the area. "Oh, but if too many people are in the area, killing one will have them spawn on top of me once I am done..." <---An actual genuine gripe? Whaaaaa... Okay, this just means you have to make note of where they spawn, and pull them into safe areas where you can escape afterwards. Open world should be dangerous anyways. Learn to group for fun, efficiency, and to prevent having to corpse run every 5 minutes.
If you argue after this, you may just be stubborn.
I love you anyways.