> So how can one explain that the economy cannot deliver relatively cheap and tasty basic food products (at much higher profit margins as the consumers are now more wealthy and more health conscious) - a task that ineffective, communist economy fulfilled with relative ease.

That's pretty simple: Poland is now importing a lot of stuff that it used to grow at home. And since Poland is not the wealthiest country it doesn't get the high priced quality stuff.

A lot of stuff that worked under communism does not work equally well under capitalism until a long period of leveling has passed. And on that front Poland has done exceptionally well compared to some of the alternatives, even so there is still a long way to go.

Incidentally, I lived in Poland before the wall fell, and of course what you should add to your story is that if tomatoes were available they tasted better, but they really weren't available all that often.