Well, it's essentially a conflict between the Christian vs liberal secular worldviews. The current secular philosophical trend is for the maximisation of freedom wherever possible so we see liberals pushing for voluntary and not involuntary euthanasia (though involuntary euthanasia is certainly a likely possibility in a dystopian, Orwellian future).
Now, of course, we have secular conservatives in both Poland and the West agreeing with Christians, but their position is difficult to reconcile with the prevailing secular ideologies. Why would you want to deny someone the right to end their lives when they no longer wish to live? Why would you spare your dog of the suffering of disease and old age, and yet force your grandparents to suffer? Would you permit euthanasia in very specific and narrow circumstances? Why not in others?
Now, religious Poles naturally, but also many secular Poles are still deeply influenced by the Catholic mindset, and so euthanasia is still seen as scandalous in Poland, even by those who do not identify themselves as Christian. But unless there is a marked shift in either the direction of secular philosophy or in the secularisation of Polish society, then it seems it's only a matter of time before Poland joins the ever increasing number of Western jurisdictions that have permitted ethanasia.
The current abortion law, which is a result of a compromise between Catholics and communists, will probably be overturned with time, and I imagine many politicians too would like it to be liberalised already, but they don't want to rock the boat and risk arousing the ire of the still-influential Catholic Church.
Sooner or later, you will get a "hard case" where euthanasia seems like a good option being covered in the media, which will portray all Poles who disagree with euthanasia in an intolerant and uncompassionate light, and once a critical mass is reached, mainstream public opinion will rapidly shift in favour of euthanasia as a result.
I had once created a thread on PF, concerning Passive Euthanasia.
Is that the same thing as assisted suicide?