Yup, exactly the kind of stuff that makes a fixed videogame world much harder to apply a blank slate, do-it-yourself character building model. Past having to DM for yourself because you get little positive feedback on your character background, you'll even run into negative, contradictory feedback, which you have to willfully ignore or modify your character on the fly.
A videogame is a limiting medium, since you're trading freedom for shiny graphics and exciting realtime action sequences. Obviously you can still roleplay diverse characters, but often you'll be shoehorning them in and competing with a 'canon' gameworld. There's an art to adapting your character to the game and weaving it with the opportunities presented to you, but in the end you're trying to put the round peg of completely freeform character generation into the square hole of a preset videogame world.
This is what I agree with.
Making up your background, as it pertains to any dialogue/reactions/responses to ingame things is kinda pointless. Since it has no affect on the story or your character's experience. However, I do this anyway, because I like to RP (and yes, I mean PnP (since the mid 90's) and a small handful of computer rpgs). I wish it had more impact. The most effective rp personality is one with no memory, since the day you get fixed up by the doc might as well be the day you were born. The only things that matter are what your character does from that day forth. Things that affect reputation and karma. Now, coming up with a character/personality can lead you to the choices you make - ie where your interests lie - helping people, killing people, whatever. So that is mainly why RP this game, to stay true to the character, and make that run through more unique, instead of just making similar choices each new character. But, I don't actually think too much about his/her past, since, it doesn't matter. I only think about their personality, motivations, and how that affects the 'now'.
I would have loved some indication of an origin. FO3, while it did make you a vault dweller with that set past, still had it's freedom. It told you where you lived until you were 18, but not your personality. The main quest was short, which kinda points out the fact that that was only a small part of the game. The biggest part of the game was having your character make his way in the wasteland, whichever way you saw fit.
NV is perfectly set up for some background options. And I don't mean anything that would limit your own RP background concept hoohah. It would make RPing better, not just stuff for a 'gamer' as someone mentioned. I don't think it would be too hard. Example.
You pick one:
Ex-NCR = like the courier, you don't work for the NCR, and you can still have all the same quests etc. It wouldn't play much differently EXCEPT: barter, speech checks involving NCR people are easier to pass. You start the game with their main base (or something like that) marked on your pip-boy. Maybe you start the game with already some positive rep with them. Conversely passing speech checks with Legion is a bit harder - but still be done.
So, you could play as someone still wanting to help the NCR, or someone who really hates them and wants to join up with Legion. Not easy, but it could be your goal.
Ex-Great Khans = similar affects. Location on your pip-boy, easier speech/quest checks. A little dialogue along those lines, showing a kindred spirit.
Repeat for the main factions. I don't think little dialogue tweaks and difficulty checks would be hard to implement. They already added stuff like that with some of the perks (see LadyKiller as mentioned above).
With this RPers can still imagine away to their hearts content, but get a little reward for their choices. Note that none of these choices say you can't be a 'kill everyone' sort of player, or whatever. It doesn't force you into any sort of personality, just give a little history (you had to come from somewhere) that makes a minor but noticeable impact on the game.
Wouldn't it be neat if you were ex-NCR, and used that to try and convince the Legion that you should work for them? Since NCR already kinda likes you, it would be easier for you to sabotage them for the Legion.
Also, there would be the option to pick no background, so all the difficulties etc were at their base settings. For those, you know, who want to be giant space monkeys. Better suited to DC, which had a couple tall structures (Captial Monument and tenpenny towers)