Actually from what I have seen in game the taxes are so bad lower middle class people cannot keep up with them and most middle class families just barely scape by with them.
And another reason would be corruption, the government is run by brahmin barons and under the table deals which will get exposed more and more and piss more and more people off.
I could see a revolution in a century if things don't improve but not forty years from now. And I don't want another time jump for many more games.
Well, if I can recall, the real-life US puts the NCR to shame when it came to corruption and coporatism, (Remember the days when the Army and the Pinkertons would violently break up strikes and dismantle unions?) and yet none of these manifested into a revolution. Political enfrancisemant is a powerful thing, it gives the population a stake in the continued existance of the government, of course, Marxists and Anarchists would argue otherwise, but that's how the mainstream citizens feel.
That dosen't mean that they can't be angry with their government, but it encourages people to try to change the system from within rather than overthrow it with force. A lot of people in the US today are fed up with the government, but if you asked even the most bitter critics if they would take up arms to overthrow the US government, I imagine you'd get a lot of puzzled looks of confusion. I bet the solutions they would offer, regardless of their race, gender, or party would be about fixing Washington rather than burning it.
And on top of that, the NCR has proven itself a pretty tough customer over the years. They have been under siege pretty much since the day of their birth, and they've stomped the [censored] out of every enemy that's tried to wipe them out. If they didn't rise up in arms after decades of war against a bunch of walking tanks with laser guns, a continued low-intensity insurgency by said walking tanks with laser guns, and a financial recession after their gold reserves were destroyed by aforementioned walking tanks with laser guns, it's a little funny to think they would rise up over taxes or some other petty problem a century down the line. I mean, as serious as the NCR's problems are, they are transitory, not systemic. The war with the brotherhood won't last forever, the economy will eventually recover, and life will go on. As far as I can see, I think there is really no catalyst for a major revolution within the NCR well into the forseeable future short of a deus ex machina falling from the sky.