I'd be similarly judgemental if Christian had been the only one to behave like this. But when you look at the field, everyone was taken by surprise by the prices. Pretty much all the major apps are closing. Were all developers hopelessly naive? All of them? I find that hard to believe.
The OP didn't even bother to read the conversation. This was announced in April, but Reddit did not provide prices. It only assured this won't be as expensive as Twitter API access, and then it actually did.
That "hope" appears to be founded on statements made to them by Reddit themselves, according to the linked post and it's communication snippets.
Or at least a much larger time to recalibrate that "hope".
Hope is not a strategy - yet appears to have been the only strategy Apollo employed.