Ahh... I thought you were talking about crimping right to the lugs. Yeah, I could see that I guess. But why not hang a wire off the main lug & then solder all your grounds to the one wire and cover the whole thing in heat shrink? Its just changing the location of the connection... and a connection is a connection.
Honestly, with a good tip on the iron and pre-tinned parts (wire & pot) I've never had a problem making things stick to the back of a pot. Or even undoing the connection if needed... Why do "they" say its a bad idea? Risk of burning up the pot?