In Morrowind, the initial speach says many stand but only one remain clearly stating you may or may not be THE ONE. Your only the one IF you decide to fullfill the profecy, IF you don t you can go to the expansions WITHOUT being the neveranine. You re not the ZERo since lvl 0 where you can hardly kill rats like Oblivion or Gothic.
Of course you can choose not to do the main quest, but regardless, IF you choose to pursue the main quest from the start to the end, you WILL be the Nerevarine, and that's the point I was trying to make. Sure, I could ignore the quest at any time and I'd never become the Nerevarine, but I never doubted that if I chose to complete the main quest, I'd be the one doing what mattered, you can go off and ignore the main quest and say you're not the one if you like And while the expansions can be played without doing the main quest, I'd argue that the story of Tribunal makes more sense if you do the main quest before doing it.
Although I wish Oblivion's main quest did away with the false sense of urgency too, but that has nothing to do with being the chosen one. It's because I sometimes feel like it's hard to justify, from a role-playing standpoint, my character going off to explore or do side quests when people are constanly telling me "Waste no time!" and "Hurry!" and such. But you don't need to be The One to get that, I mean, I've gotten people urging me to hurry in real life too, and it had nothing to do with being a chosen hero.
Also in Morrowind many WERE called the NEVERANINE and FAILED, so you re only one more pretendent to the bride, nothing less, nothing more.
The fact that some people were said to be the Nerevarine and failed doesn't prove anything. They failed because they didn't meet all the conditions of the prophecy, or they failed while attempting to complete the tasks that were part of the prophecies. In fact, I seem to recall all the failed incarnates were native Dunmer, so really, they weren't qualified by default, since the prophecies say the Nerevarine will be an outlander, of course, they didn't know that when they tried, seeing as it's one of the lost prophecies. A chosen hero must obviously be able to succeed where others would fail, after all, that's sort of the point. If anyone who tried to be the Nerevarine could do so, there would be no point in all those prophecies telling us about how the Nerevarine would be born under a certain sign to uncertain parents and all that mysticism.
In Daggerfall your a mere shadow courrier and then you become IF YOU WISH the SAVIOR or a VILLAIN.
Since when did anyone mention Daggerfall?
But regardless of what choices you made in Daggerfall, you're choices would change the course of history, that's why the Warp in the West was needed, because Bethesda couldn't just keep it vague which of the possible endings you chose. So in a sense, you were still the hero. Sure, maybe you wouldn't choose the path that one would necessarily see as good, but I'm sure whoever's side you chose when it came time to do so would call you a hero.
Remember in the beginning of the Thieves Guild when you and those other two people had to steal that guy's journal and whoever got it and returned it was inducted into the Thieves Guild? Maybe we could have something like that. And the fact that you did steal something was why you were in the competition, because they knew that you were, to some extent. capable. And if you don't win the first time you get a second chance.
That's a bit different as it's a guild questline, not the main quest, and of course the guild questlines will start out simple, because you're new to the guild, and obviously no one is going to trust the most difficult and most important jobs to the newest person in the group. Really, I'd argue that all the faction questlines are like this in Oblivion, except the Arena, since that was just kill progresssively harder opponents in the Arena until you go up against the grand champion, with an optional quest that makes him not fight back at all, if you complete it. Not much room for a story there, although I suppose it was somewhat more striking in the Thieves Guild than some of the other factions since I would have not expected to go from stealing someone's diary to stealing an Elder Scroll from the library in the Imperial Palace.
Let us not forget New Vegas which, while it was not made by BGS, had a lot of interaction between gamesas and Obsidian so I'm sure a few lessons learnt in its development got passed on (varied voice actors, for instance). I am also sure that the fine folks at BGS played New Vegas's main quest and really appreciated the freedom to carve your own way through it.
I wouldn't be at all surprised if Bethesda took a few ideas from New Vegas, in areas that it did well and that might work well in the Elder Scrolls too, but it waits to be seen if it's multi-path storyline will be one of those ideas.
Mind you, it would be interesting to see this level of choice in Skyrim's main quest, although I fear that if it lead to multiple endings, Bethesda might adress the issue of how to make it work in sequels using another Dragon Break, but I wouldn't bet on it. After all, this sort of story isn't that easy to do since you need to write a number of different questlines, instead of just one.