It seems accessibility would also be an issue,which would be in direct NEC violation. You'd have to pry out an outlet and the wire for service and/or inspection. I don't like it.
As for peope letting drywall mud and paint into panels, almost every interior panel I've opened that was installed prior to 1980 has an absurd amount of crap in it. Apparently they had not heard of masking off anything that the buyer would not normally see before purchasing the house. This usually includes te busses as well!
