Yeah, the things it though, the Scots picking on Scots thing is actually very serious.
In Scotland you have "The Catholics" and "The Protestants" and they hate each others guts. To the point where in Glasgow they made seperate schools for each group and let them out of school at different time (to stop the kids beating each other up.)
Look up domestic violence in Scotland. It often shoots up when Rangers play Celtic. This is because Rangers is a Protestant team, while Celtic is a catholic team, and the two groups split along those lines. When Rangers lose it isn't just your team, it's your whole religion losing. So you get drunk, and then beat your wife/kids.
So yeah, the Scots vs Scots thing isn't quite love/hate, it's more just hate.
Edit: Just a note, this is really a West of Scotland thing, primarily Glasgow. In Edinburgh it's alright.