You say that, but what comes to mind is the scene from Hot Fuzz where Simon Pegg's character needs a translator to understand a thick West Country accent.
(I'm pretty sure his accent is exaggerated on purpose)
Close your eyes and _listen_, don't be distracted by the video.
Just Clarkson hamming things up.
We're simply comparing ability to distinguish other regional accents on the Island, not putting each other down. Generally folks here get to hear lots of different forms of spoken English.
and no - I ain't no "accent genius", there are parts of the Scouse, Brummie, and Durham accents I have trouble with.