Huh? The Apollo dev was very specific about why he couldn't make it work. The turnaround was too fast. He had users on multi-month and even annual subscriptions. Users who were effectively owed service by him. The new model would have turned all of those users into giant financial liabilities for him far beyond whatever revenue he earned from them. And theoretically there was no upper limit on how much those users could have cost him.
If they'd give him 12 months notice about the changes instead of 30 days he would have been able to keep the app running. It would have cost quite a bit more as users would have had to pay for his costs plus the api costs. But with only 30 days the only financially sane thing he could do was refund everyone, rather than let them turn into liabilities he couldn't afford.
If you're wondering why he didn't refund all existing users and then roll out an update with the higher subscriptions... I mean, I'm sure he just didn't want to because he didn't feel like it after being forced to go through all that terribleness and repeatedly being defamed by the admins.