I saw a guy at the shop last Tuesday blast a door panel clip with his impact and snap it clean off. Those things are designed for like 5 ft-lbs max, not 200. Now the customer is out $40 for a whole new panel because the clip housing is busted. How many times do you have to replace a trim piece before you grab a ratchet instead?
Read somewhere that mechanics in Japan use torque screwdrivers set to like 3 ft-lbs for interior trim and they almost never break anything. Maybe there's a reason for that.
My buddy works at a dealership and he swears by using a 1/4 inch impact on low setting for door panels, he's done it for years with zero issues. I'm not saying the guy in your story wasn't a moron, but a 200 ft-lb impact gun on a plastic clip is like using a sledgehammer to hang a picture. Maybe the problem is people not knowing which tools to use for what job, not the tool itself. I've got a cheap cordless ratchet that'll break those clips just as easy if you crank it by hand too hard. It's what you do with it that matters, not what you grab.