I think this is very sad...i have a good roster, PO Pro´s, Star Pros etc., Level PO++ all earned by playing, not spending money (invested 20,-Euros at the beginning 2015).
I´d really like to have Hall of Fame, Legend etc. cards, but without spending money, you have no chance, even winning the cards is nearly not possible without spending money.
At the end it would be ok for me to spend some money for these cards, but not if the app will be shut down in the near future...