Broadely , I would attribute it to things getting worse. And the increased awareness and reaction to things getting worse.
Sliding it neatly in with the rest of the modern pantheon of stories where, they don’t contest things are bad. It’s just that the villains want to solve the problems in a way that’s worse.
That Riddler was literally a cryptofascist, that's the worst example of this trope they could have chosen. He's not fundamentally different from any 4channer ranting about (((them))) on /pol/
Sure, there's probably going to be some populist rhetoric in that, but he was a very specific archetype of populist.
Also it doesn't help that Gotham is literally cursed.