That explication doesn't explain why there are polish cards in euros, USDs and british pounds. These were clearly to be used out of Poland. At most, one could say the cards were to be used abroad by polish or polish residents, as they seem to have said
https://bitcointalk.org/index.php?topic=775730.msg8758459#msg8758459.
But it seems this is a new policy, because:
a) Their website to check cards have several languages.
b) As far as I can recall, their agreement says nothing about the cards being allowed only to residents.
c) To limit their financial services to polish citizens is a clear violation of European Law that demand equality between all european citizens.
And some cards that were only used abroad and were recharged using foreigner banking accounts are still working.
They are just making excuses to keep some money.
There was never a policy for use only in Poland or by Polish citizens only.
They say that because they can't block cards from polish users or their branches would be on fire right now.
Scammer users (polish or international) won't complain because they know they are scammers and it's pure profit for mBank.