Let's look at a few examples of story quests. First, there's MacCready for Action, which is the story of your companion Robert Joseph MacCready. MacCready's a returning fan favourite from Fallout 3, where he served as the adorably obnoxious child mayor of Little Lamplight. He's a fully grown man now, and after a few hours of passionate lockpicking he will reveal his tragic backstory to you: MacCready's wife was ripped apart by feral ghouls a few years back, leaving him to care alone for a terminally ill son who is suffering from an unknown disease. MacCready has set out into the Commonwealth in search of a cure, and he needs somebody to help him follow the quest markers. Half an hour of pew-pew later, you hold an experimental cure for an unknown disease in your hands, and now you're off to try and see if it will cure the kid! No, actually you aren't, because the kid is lying comatose in a shack somewhere near Washington D.C., and that's outside the game world. Well, then MacCready has to go and try to cure his kid himself! Goodbye Robert, hope you and your spawn find happiness! Ah, but no MacCready is bound to you, his lord and mistress, and will not leave your side. Instead, he gives the cure to a caravan master he trusts, sends it off to his son, and then the quest is over and the story's done.
And here's my analysis: Jesus Christ, are you fucking kidding me? Why the hell wouldn't the guy go home to his dying son? Is he mentally ill? Why can't I order MacCready to go? His kid is dying! The cure may not work! It may kill him! He may already be dead! Why does the game build up such a strong thematic connection between the PC and MacCready (dead spouse, son in distress, now they're scouring the Commonwealth for a solution), only to fuck it all up by saying eh, that dude's kid will be fine, he's just suffering from an unknown fatal disease with an experimental cure and may very well be dead already. Your kid, on the other hand quick, let's have another emotional dialogue! Start quivering, girl! This type of writing is not merely self-defeating, but it's actually harmful to the game; until I played through this quest, I had no idea what utter hacks Bethesda's quest writers were. After this uncomfortable episode, I never used MacCready in my party again; when the main quest was over, he was still hard at work tilling my fields.