Actually I don't think it's that far fetched...IF Costa Rica beats Ecuador, and that's entirely possible, the group would probably be decided on goal difference with Germany on top and Poland, Costa Rica, and Ecuador all on three points. Poland could then almost still control their own destiny by bringing everything and really running up the score on Costa Rica and praying to go through on goal difference.....Right?
With two losses you can stick a fork in Poland.
Too many other things would have to break perfectly for Poland to advance.
For one thing, Ecuador would have to lose twice and that's a lot to ask. I would expect them to at least draw Costa Rica.