This kind of behavior has sprung a whole new generation of ignorant people, and your seeing with this kind of behavior when they visit Poland.
I think it's because most people living in the west can't grasp it. It's impossible to understand such a thing because most of us have never endured something like that. It's not so much ignorance, just inability to grasp. What's left is this anger. Many Jews who survived WWII had a negative experience prior to and during it, so, this has left them bitter and traumatized, as I'm sure Poles are too after going thru it. It seems both Poles and Jews are equally as traumatized and you can see it reflected in these posts on PF.
Younger Jews in Israel listen to these stories from survivors of Auschwitz and it pisses them off. It's understandable why it would because it's just so difficult for to comprehend unless you have lived through it. Back then, nearly everyone in the world had much less than we do now. To even begin to understand, we would need to start life with far less than we do.
I don't doubt some of the Jews, in an effort to survive, did things that put other Jews in danger, maybe without even realizing the consequences, like,with Jewish councils in the ghettos. They sent their fellow Jews to labor, maybe without realizing what would eventually happen, or maybe they thought they would be sentenced to death if they didn't? Same with the Poles.
You read about nobody stopping the trains by sabotaging them and how some think it was because no one wanted to. What remains unsaid is, if someone did stop the trains, there would have been hell to pay. Even if they tried and failed, the consequences would have been harsh. The Nazis, I'm sure, would have retaliated in an extreme way.
A rebellion occured in one of the camps, all perpetrators were killed. I'm sure if someone would have tried to stop the trains they would have been killed along with everyone riding. Who knows, maybe even more.
Many Poles did help Jews but so many Jews ended up in the camps it's hard for them to focus on those who risked their lives. So what they do when they visit your country is act out. It's no excuse, but that's why they do it. Another thing I'm sure, aggravates them, is the grafitti condemning Jews. It's in places in Poland. That probably pisses them off as well because it reminds them of the terrible past.