So, best guess is that it has to do with the 100 coin gift. Maybe the game detects the player has money and that prevents triggering the event for you to start earning money, which as far as I can tell is the gateway into pretty much everything else.
As a test, I reverted to a save before getting PATS, then tried getting rid of the coins by repeatedly passing out in the Western District, then occasionally saving and trying to buy something from Aero, reverting to the save when it doesn't work. There's nowhere for me to see how many coins I currently have, and I've no idea now much is lost per incident. I've done it a dozen times so far, but still get the same result when trying to buy something; it doesn't give me a price, but acts like the purchase was successful.