Somebody told me this in a youtube comment yesterday
P&S was made by Imaishi and co. back when they were still with Gainax. While they left to form Trigger (and have admitted they'd LIKE to do a second season), the rights are still owned by Gainax. So, the creators want to do season 2, but can't; the holders know better than to do a second season without the original team behind them.
https://www.youtube.com/watch?v=1-4CYB2G8eY&lc=UgxqiaZJD4B8tEcvdWd4AaABAg.8vDF9qll5iX8vUfDb2VrejCan we only hope that one day these two studios will work together again to make our dreams come true???