I'd just like to say that you are absolutely NOT just some random nobody in Baldur's Gate that no one cares about. You're (one of) the living incarnations of the God of Murder and your very existence is part of a plot by the Bhaal to return to power after his death during the Time of Troubles (when all of the gods were turned mortal). The entire plot of the games revolves around this fact; the first game even opens with another one of your "siblings" attempting to murder you. By the end of the series you've killed the prince of all demons and possibly become a God yourself.
Anyway, part of roleplaying is that if an activity ingame doesn't fit your character then don't do it. If it doesn't make sense for your character to be the archmage of the mage's guild then don't become it. If you don't want to be the savior of the world then just abandon the main quest after the intro. With that said, I agree with the premise that the world should do a better job of acknowledging who you are and what you've done.
All true, but the people walking around don't know your dad is Bhaal. The dude behind the counter at the store (Ribald, I want to say?) doesn't know you can turn into a demon at will, so it makes sense that he treats you just like any other sap that walks in. Same with the city guards.
Regardless, I don't like the argument that I can
just not do the main quest. Why? Two reasons - (1) my existence in the game has no overriding point, and (2) it doesn't make sense that my character would just blow that off. From basically the get go, your character knows that the world is under attack by dragons and that he is a super powerful "chosen one" type who can absorb dragon souls and breathe fire. Even if he weren't interested in saving the world from dragons necessarily, he would stlil want to investigate that whole "super-powerful chosen one" thing. It just doesn't make sense to blow it off.
Similarly, in Oblivion, I hated the apparent urgency of the main quest. Uh oh, emperor gets murdered, demons are invading, you've GOT to get this necklace to Weynon Priory or we're all screwed. It doesn't then make sense that my character would spend a few months picking flowers, learning about alchemy, raiding ruins, practicing archery, or whatever, before heading to Weynon.
Also, it made no sense that the blades guarding the emperor were so quick to take your word on what happened when they had their backs turned. "Oh yea, that guy killed the emperor, not me, and the emperor told me that I was the chosen one and I have to take this invaluable relic to this dude (but not after I become the archmage of the mages guild, thieves guild, etc)."
Bottom line, if Bathesda worked on their storytelling, then combined it with the worlds they're so good at creating, they'd have the greatest RPG of all time on their hands. They could even go back and literally re-use the Morrowind world, update it with the new graphics and whatnot, and then spend the rest of the time on dialogue, story, mechanics, etc., and it'd be an amazing game that I'd pay $60 for.