It's not a bad thing to love your motherland and your culture.
It becomes a bad thing when this love becomes a "national pride" and the absurd belief that you (and your people) are better than others because your ancestors were born into a specific culture or land. Then you become easy prey to the nationalist zealots who preach exceptionalism and intolerance.
All it takes to get out of this mindset is to travel a lot, possibly live in a couple of different countries and experience a few different cultures etc. If you've lived in a few different countries (and both ajax and I have done that) and if you also travel a lot you'll soon realize that at their core most people (from any culture) are the same, or at least very very similar. There are nice people and there are jerks wherever you go, no matter if they're Greeks or Turks or Italians or Brits or Indians by nationality.