I guess we could take this approach to every side mission, in every game ever, not just RPGs? Why would I investigate an iron shortage, and inferior iron, when I just witnessed a party kill my foster father coming after me? Why couldn't I just tell the dwarves "help me fight the blight, or don't look to us for help when you're overrun by darkspawn"? Why couldn't I tell the Normandy crew to deal with their side issues while I pursue the main quest, and still succeed at the Suicide Mission? I'm sure there's an exhaustive list of side quests I could prattle on about, but the fact is, they're all over the place in gaming, from Table Top games to MMOs, and they have been, forever.
