Dear foreigners! You are all very welcome here in Poland, but if you are looking for a good job (excluding teaching English), you have to learn Polish.
I simply don't see how knowing Polish is all that lucrative as a foreigner. if you're here as a foreigner working for a company, you're probably already hooked up with salary, company car, hotel/apt., etc. Sure, learning the language is great, makes life easier, but it's generally not gonna put more money in your pocket. You're getting paid the salary you are because you are NOT Polish. Also, most of these people have contracts of 3 years max, and then they go back to their country and speak their native language again.
If I was from a non-English speaking country and I got transferred out here for a 1-3 year contract, I'd take English lessons over Polish lessons, and that is exactly what all the foreigners in Poland do when they aren't native English speakers. I know, because I teach them, and their reason for doing it is always the same.
Regarding expats, eliminate the English teachers and corporate transplants, and you're left with a negligent amount of people.
Your statement doesn't make sense.