Fast forward 50-70 years, we realize that the balance has swung too much to one side so we try to do a sharp turn. That action causes an overcompensation which is when revolution and violence happen. Finally we end up back at some sort of liberalism and the circle begins anew.
I see it as a result of generation gap. We don't know the value of something until we lose it. Right now the public doesn't value freedom of speech as much as it used to so we are right on track to have it more limited.
As with many such rituals, -and as long as everyone sticks to the prescribed acts- this reduces the bloodshed immeasurably. With a little luck, the only victims are dead trees and broken pencils.
Currently we are at the bit of the loop where the underclasses are thrashing out and the elites are trying to channel that rage somehow.
Even if it's a matter of picking the right start and stop times to a cycle, every iteration would be heterogeneous enough that calling it a cycle is probably missing some important behaviors.