The thing that I've seen pretty consistently from both RIF and Apollo devs is that they're not disputing the fact that reddit needs to start making a profit. Nobody's (seriously) complaining about what was free becoming not free.
The fact is, if this was purely about money, they'd be willing to negotiate on price. The price they're asking is ~70x more than imgur, which hosts images WAAAAAY heavier to host than text, and links etc.
If it was solely about showing ads, they could have given 3PAs access to reddit ads via the api, and enforced showing them.
There are several ways this could have worked for everyone.
Reddit wanted to kill 3PAs. That's the only logical conclusion here. Hell, if they'd come out and said THAT, as well as fixing the problems with their own app first, I might even have been able see their side of it. I would still be pissed, but it'd be more understandable than this very blatant Twitter-esque death-by-pricing thing they're trying to do.