personally i think theyre not only stupid...but somewhat insulting.
why on earth do i need an achievement telling me i completed a quest? especially main plot quests. the notification in game is enough.
an "achievement" is something you accomplish thats difficult...following the main plot is what you are supposed to do, theres no reason to have an achievement for it.
they are just stupid little nothing things for console kiddies to collect.
i dont need them and i dont want them. id be surprised if anyone over age 11 even looks at them.
having them in a game like fallout cheapens the experience.