Why is Polish food not better known?

As a foreigner who recently discovered Polish food, I'm amazed that it's not more widely available or better known in the rest of Europe/the world. I really love pierogi, krokiety, flacki, etc. - it's all delicious! I know in big cities like Warsaw the traditional cuisine is also being given a modern 'makeover' so that it's not so heavy/rich and appeals more to young people, but it's still scrumptious.

Why have Polish emigrants not set up restaurants abroad and why do celebrity cooks such as Jamie Oliver and Gordon Ramsay seem to be ignorant of Polish cuisine?