I've found a difference between the mashed potatoes you typically get in England to those in Scotland.
The stuff I've seen, and been served, in England is so wet it no longer resembles potato but wallpaper paste. It doesn't stay in a fluffy mound but settles and spreads across the plate.
Scottish mashed potatoes are nowhere near as wet, despite using a bit of milk and/or butter. There's still a structure to it.
Obviously people will prefer what they've been brought up with but only Scottish style mash is acceptable! 😃