Beginner Trap: Movement for 'Cinematic Effect' vs. Flat Staging?

Hey everyone, Raj Patel here, I’m a focus puller normally, but I've been trying to DP some smaller passion projects with a C70 and my AMIRA. I'm hitting a wall trying to instruct newer directors and DPs on what to avoid. I keep seeing two major issues, and I can't decide which one is more fundamentally damaging.

Option one: they'll often just start moving the camera (on a slider or gimbal) for absolutely no narrative or emotional reason, just because they think it 'looks cinematic.' It’s all smooth pushes and pulls, often on a character just standing there. Option two: their blocking is super flat, all actors on a single plane, like it's a stage play. No use of foreground, background, or depth at all.

I’ve tried explaining both, and sometimes getting through to them is like pulling teeth. We'll be using an Orbiter and some PavoTube II 30Xs, trying to create real atmosphere, but then the camera work or staging just undoes it. Which of these, in your experience, is the single most destructive pitfall for beginners to fall into?