I'm trying not to pre-judge you, but you write
they are able to express their ignorant opinions more easily.
And then follow with
their backward views about air conditioning
It makes me wonder exactly the type of conversations you have been having with Germans for you to say
Germans are incredibly sensitive and defensive about any perceived criticism of their own culture or system
Perhaps without realising you are being overly critical of them? You are not in your home country and people always tend to compare how things are at home, sometimes negatively, with how things are in the host country.
Could this really be any worse in Poland?
I would say that the times I have spent with friends in Poland in winter, and in Poles' houses here in the UK, temperatures are bordering on tropical. They like it warm!
Do Poles always insist that Poland is better than the country of the person they're talking to?
I haven't come across many that do, but I've had plenty of discussions with them about differences between the UK and Poland. There are many things they miss about their own country, but by and large most of them seem to prefer how things are in the UK.