I think it happened as they took power. Like the difference in behavior of the minority Muslim group that transitions to a majority.
They start by complaining about oppression and finish up wandering the streets beating people that don’t adhere to Sharia law.
Much like the gay movement here, now that I think of it.
I think your observation apt. If one casts one's self as a victim, then one also casts another as a victimizer, a la the “takes two to tango” model.
With so many playing the victim these days, it seems many will want to force others to be their chosen victimzer, to justify their will to violence.