From my (ethnic Polish and fluent in the language) friend's recent visit to Poland, I gather that the atmosphere there is quite religiously oppressive, much like Ireland in the 50s/60s. I suspect that many of the migrants are young people all to glad to get away from it.

On the other hand, if it becomes a nationalist and communalist issue, as it did in Ireland in the late 19th/ early 20th century, religion becomes more entrenched. No surprise, we are seeing a similar phenomenon with Islam in the Middle East.