I don't buy the 'he wasn't getting a game for Scotland' argument. If you're getting on a bit, and you know you aren't going to get picked for your home nation (i.e. don hutchison, ray houghton, lorenzo amorouso (almost played for scotland :D) then fair enough. But he made the decision when he was still a teenager, as did McGeady.
There's nothing wrong with being proud of your ancestry and heritage. But if your personal identity and national loyalties lie with Ireland (or ANY other country) over Scotland, as is the case in some communities in the central belt, then that's an unhealthy state of affairs IMHO.