You get fresh fruit and vegetables throughout the year, dear, however if you wish to buy some strawberries, say, in February, there's no chance to get them as cheap as in June or July and without a label, since we don't grow strawberries in winter.Look around.
Besides, I don't know where you shop but I feel sorry for you if you can only buy rotten vegetables or fruits. Since what you wrote above implies that Poles don't eat them at all or only in small amounts due to the fact that to whichever shop they go, the fruits are rotten.lol.
What's more, you can buy "cheap, plastic cheese" in every country, Poland isn't an exception. When you want to buy a good cheese or a good ham (polish btw), you have to spend at least 50 zlotys per kilo for the cheese and round 80 zl for a good ham. And I'm sorry, but my country isn't a rich country, so there's plenty of cheese which is cheaper so that everyone can afford it.
Pretty much everything is substandard there when it comes to food in my experience. But then I don't like white doughy crap, cabbage and pork with everything.
if you don't like it...who tells you to eat it,eh? Go to a decent shop and buy what you like or buy the ingredients and prepare it yourself.