I don't like the English much, and I am English. You get a lot of anti - English banter in Scotland (and Wales, and Ireland, and even Cornwall!), but most of it is just that. Obviously there are a few of the usual bigots and young males who take it a bit far. Pointless making a big deal of it, is just part and parcel of the way the UK has been formed.
I suspect in Murray's case he's probably genuinely outgrown what is a pretty common meme. Not that I'm a massive fan or anything, he's pretty dull!