That's because I doubt many of them have ever actually been. I spoke to this guy who was at Eton College once:
Me: I'm going on holiday to Blackpool.
Guy: Why? It's a dump full of chavvy women on hen nights.
Me: Have you actually been?
Guy: God no, of course not!
I went to the cinema on Friday to see 'Snow White and the Huntsman'. The huntsman was an alcoholic, violent Scot
The media perpetuates these ideas. And because there's so many more English people than Scots, of course no one in England is going to want to admit they stay in the roughest place, and so will vote for Glasgow to make theirs look better.