Do you think it matters if getting a large number of people to switch to tabs is an achievable project at all? Maybe I am a bit cynical but this seems to me like something that is actually very difficult to do.
When faced with a problem like this I think it makes more sense to approach it from a perspective of what would be a practical way to actually address it and refusing to do that does I think in its own way betray a different kind of cynicism.
For the record what I'm saying isn't that I wouldn't switch to tabs for the sake of people with various disabilities, I'm saying that spaces are slightly better than tabs if you don't have any relevant disabilities so if there is a way to have the cake and eat it to that would be a nice bonus, but that's honestly besides the point.