ZAPROSZENIE? (visiting our Polish friend this summer)

We decided to visit our polish friend this summer and my Polish friend went to local gov't office to apply ZAPROSZENIE whatever that is for my mate who'll be travelling with us (not aussie citizen yet) . My polish friend was told they are too POOR to apply ZAPROSZENIE and therefore cannot invite foreigners to visit Poland. We are speechless.

It is not that they are too poor to apply for zaproszenie/invitation but more likely they do not meet income criteria required to get such document. They would take fiscal responsibility for the invited person in case of his/her any medical cost while in Poland and also would face fine if he/she wouldn't leave Poland.