Polish American checking in: Because Catholicism. Catholics are universalists. There is no one that is meant to be outside the reach of love of neighbor and thus out of reach of the Church. It's a naive evolutionary strategy to expand the faith as far as possible so as to create a worldwide theocratic utopia. It's obviously a degenerate idea in practice, but since Poland is very homogenous they project European theory of mind onto other races and would feel like they are endorsing what happened to them in history by being invaded by racist Germany. The real reason they reject migrants is because they practice Islam, not that they are brown.

Look how close the recent presidential election was there. Liberal universalism is widely popular, its mostly gay and trans people that prevent the full embrace of it. Poles are wary of racism, they still feel somewhat victimized by it themselves. They need to be exposed further to race science and shocking media before they stop clinging to religious hysteria so closely