This really feels like a case where the reviewer's pre-set assumptions (Chopper Is The Worst) got in the way of him seeing what the episode (and the show) is actually doing with the character.

Oh, yeah.

I don't think the plot is that hard to understand…? Catastrophe and Arsyn are running a corporate heist together, but at the last moment Arsyn betrays her partner. She steals the package and throws Catastrophe out a window.