There are plenty of reasons to criticize Starlink. Kessler syndrome isn’t one. All of the satellites are in such low orbits that they will decay relatively quickly without maintanance. As long as they have fuel they can move out of the way, and when they don’t they will burn up in the atmosphere.

Them ruining astronomy sucks. Them fucking with Ukraine suck. A lot of other things they’re doing sucks. They aren’t actually polluting orbits in any reasonable interpretation though.