@Booldawg - exactly what I was about to say. Whenever I hear anyone say "I hate the [name of an entire nationality]", or make any sweeping statement about a nationality, they simply sound really, really stupid. They often then try to hide behind that catch-all piece of self-justifying inanity, "Oh come on, it's just a bit of fun"
You do sometimes hear about Welsh and Scottish people cheering on whoever England are playing; I'm sure that happens, just as I'm sure there are people who sieze on historic wrongs to allow themselves to vent some spleen.
I don't know Wales very well outside of a few childhood holidays but am in love with Scotland. I've been to the lowlands, highlands, the western and northern isles, and loved it all - the landscape, the cities, the people, the food. And no I'm not talking about deep-fried battered haggis.
I've spent a fair amount of time in and around Glasgow and never had any problem with people or accents. And the highland accent is one of the most beautiful ways of hearing the language spoken.
If a Scot ever voiced hatred at me for simply being English, apart from protesting that all my ancestors were scattered among Goa, Portugal, Ireland and Wales, all I could say back would be, well I love Scotland (but I probably wouldn't like THEM very much).