Change, even if subtle like with New Vegas, isn't impossible - both Beth and Obs got some flak from their handling of the franchise. Wait until Fallout 4 comes out before starting to drive people off, that is pretty much the point when it is settled what we can expect from the future.
My main problem with New Vegas, is the lack of real exploration as well as enemies. Make no mistake, I do not hate New Vegas, I just came away a little disappointed in what otherwise could've been a much better game had Obsidian had more time to develop it.
I do agree that change isn't impossible, and people do tend to dislike change, but without change Fallout would turn into just another cookie cutter type game that comes out year after year with no significant changes made.
other people have floated an interesting idea recently, an idea I kinda like but am also aware is unlikely to happen; a team effort, so to speak, between Bethesda and Obsidian on the next Fallout title (most likely Fallout 4). The best of both worlds, but even then someone somewhere will find something to [censored] about.