Furthermore the priests were not killed for being priests. They were killed for being Polish Nationalists and for hiding Jєωs.
And what is wrong with that?
I agree, Polish Nationalists should be left alone.
As long as they stay in Poland and do not attempt to subvert within other nations.
I agree there is nothing wrong with being a Polish Nationalist (if you are a Pole). However as a priest you can not involve yourself in the Polish war effort or engage in secular political-nationalist polemics and expect not to become a political prisoner if you are caught by the invading country (in this case Germany). If you involve yourself in these things, then becoming a prisoner should be no surprise. It "comes with the territory". Though it is interesting that there was no problem with the priests in France, Belgium, or Luxembourg when under German control. If people were being killed simply for being priests then there should have been persecutions here too, but there weren't any.
As for hiding Jєωs that is a huge problem and the main reason why Poles were persecuted so badly by the Germans. Hundreds of monasteries and churches kept Jєωs in them and tried to protect them. Remember that they knew nothing about "gas chambers" either. All they knew was that pestilent Jєωs were going to be deported to detention camps. This is not any worse than when popes deported Jєωs to the ghettos, or when the Holy Isabelle de Espana expelled the Jєωs from the whole country of Spain. They knew nothing about gas chambers, so they knew the Jєωs would not be killed, but they still tried to protect them merely from deportation because they lost sight of how evil the Jєωs were. Poles and Jєωs lived together for centuries and grew very close to each other much like Jєωs in the USA. To the Poles the Jєωs were just innocent friends who deserve liberty.
The priests and religieuse in Poland also falsified thousands of baptism certificates for Jєωs and that was also a problem. The Poles essentially allowed thousands of Jєωs to infiltrate the Catholic Church and pretend to be Christians merely to avoid being deported. This is a main reason why so many priests were sent to camps and were killed (intentionally or unintentionally).
In closing the priests of Poland could be considered Polish Martyrs, or Martyrs of the Polish Nation. But as a Pole I would be ashamed to call any priest who helped Jєωs a Martyr for Poland. They are really Martyrs for the Jєωιѕн cause. They are definitely
not Martyrs for the Catholic Religion.