Discussing the effectiveness and costs of different actions is not tone policing or respectability politics. It's an inescapable part of organizing; you have to think about what you're going to do and what result you're hoping to achieve.

Getting in trouble isn't a hard barrier to action, but if you're going to get into trouble (and ask those around you to get into trouble) you should have something to show for it. If someone is trying to talk you into getting arrested in a way that will not achieve anything significant, yeah, they're either a cop or doing a cop's job.