Revolution sounds like a magical cure-all for bad government when you're chatting around your buddy's dining table, but in practice it tends to be excruciatingly horrible. Lots and lots of innocent people get killed or brutalized (by both sides--revolutionaries aren't known to make fine distinctions between murderous jackbooted thugs vs. guys who think maybe the old regime was okay sometimes); lots more suffer from the loss of utilities, emergency services, and general civil order; and even if the rebels win, it's basically a coinflip whether the new government is actually any better than the old one.

The Revolution hasn't happened yet because the closer one gets to putting it into practice, the more apparent all of this becomes. You don't get a revolution when things are bad. You get a revolution when things are so inhumanly awful that mass death and chaos starts to sound like a step up.