Stereotyping is based on perceptions and thus on reality. I've met some wonderful people and some equally vile people all over the world. I've met generous Scots, and my Dutch friends are the most generous people I know, I've met Germans with a sense of humour and I've met dishonest Swiss, and Aussies with no sense of humour at all. There are always those who belie the stereotype.
I have met a lot of people from Northern Ireland both globally and in their own territory and they seem to have a far larger proportion of big-hearted outgoing folk there than in many other places.