This is actually one of the most disturbing and irrational things I’ve seen the Pope say so far. He’s very fond of railing against “legalists” and “Pharisees” and people who are not as humble and merciful as he is, although I’m not sure exactly who these people are. It’s true that there were once Catholics who were perhaps a little obsessed with the possibility of sinning, but that related to themselves - this was called “scrupulosity,” and actually was itself something that could be matter for confession. That is, fixating on one’s sins or the fear or possibility that one may have sinned was wrong in itself.
But these supposed Pharisees that the Pope keeps attacking now are straw men, in my opinion; legalistic, ritualistic Christians really aren’t the problem in the Church, and if anything, it’s Christians who don’t know or care about any of the laws of the Church (including basic moral law) who are the problem. But his attacks on these non-existent people look like and are interpreted by most of us as attacks on people who adhere to traditional Catholic practice and morality, and many such people, who really do their best to be good Christians, feel unfairly targeted by the Pope, of all people.
This was a particularly cruel attack, in which he accused them of having “stiff skins” (I assume that he meant prim and rigid faces) but “rotten hearts” and then he went on to say that he hoped they would slip on a banana peel and be angered with God and thereby sin themselves. So while his words were incoherent to begin with, no matter how you look at them or interpret them, they are certainly spiteful and cruel. He doesn’t seem to think much about what he says before saying it, so he probably didn’t mean it to come out like that, but it’s very hard to take it any other way.
Modernists tend to use the word “rigid” when describing true Catholics.