Reddit is, at the moment, purposely expensive to run. They could have chosen to be a much smaller operation and act as stewards, but they want to turn a Craigslist into a Facebook.
OpenAI will get the data one way or another. Frankly they’ve probably got about as much data from Reddit as they need. The user base isn’t against Reddit moving to monetize and they aren’t sympathetic with OpenAI getting a free ride, these are weak strawmen. There were ways to accomplish both of these goals that wouldn’t involve this change, but their real goal here is to kill off 3PA and it’s very transparent.