But don't you think that your (grand)parents may have been more motivated due to having children and grandchildren? Now, why an old, childless lady or man, living on pension, would take risks, especially when they lived their life watching things taking shape? Again, some will act on principles they believe in, but such people are always a minority. And I doubt people in age of your (grand)parents constituted a bulk of protesters.
I am from Poland. When mass workers protests were happening under communist regime, age median was under 30 yrs. Today it is over 40 yrs. Even excluding other aspects (like liberal ideology taking a firm hold here, and real economic growth that happened since), people today are much more complicit, and much less willing to take direct action, even if today's government is much less likely to beat you to death in jail.
Won't happen in a society where elders are more numerous than young. In the past it required a lot of young males thinking they have not much to lose, but they are becoming extinct.
Old people won't revolt, middle-aged fathers that need to think of their children and mortgage won't revolt.