I would think that copper like that would be too malleable and therefore be prone to deformation when you step on the foot switch. I’ve done copper faceplates though, using thin copper sheet. I’ve also rolled sheets out from copper pipe by cutting it from end to end, bending it into a c-shape, and pressing it flat in a vice (def not the best method, but it gets a decent sheet from pipe that would otherwise get scrapped)
That all depends, really. It's a good point, but there are things that can be done.
Hard-drawn copper is stiff as hell. Heating will anneal copper, but it can be re-hardened through work: hammering, bending, etc.
The pipe grade would be important too: DWV would be extremely easy to work with, but would be unlikely to be structurally sound of one makes an entire enclosure out of it. Type L would make for a pretty robust enclosure, though.
One could always rivet some aluminum angle below the switch on the inside as well. That would reinforce the most vulnerable area.
Granted, a soft-touch momentary switch/relay bypass would likely be wise in this sort of setup. Best not to tempt fate.
It's certainly not the sort of thing that would make for a "production" enclosure. One offs? Absolutely.
I've been playing around with the concept of "electronics as art" in my head for a little bit. Folks on this forum do some truly amazing stuff with point to point wiring, tag boards, graphics, etc. Guitar players already have a tendency of fetishizing the rare diodes and transistors and chips and voodoo of certain pieces of equipment. So if that's the case...what's to stop someone from scamming some rich asshole guitar player with far more money than sense into buying a pedal that is functionally identical to something they could get anywhere else but just looks really cool?
Fuckin, game on