Don't know, but there are more points to the compass than profit and loss. It's not hard for me to imagine that a site like Reddit, with a billion engaged and trusting users could add value to the companies that control it, without it being a profit centre directly.
And I added an edit to point out that if the profit motive was true, they would have accepted the money offered by the API users who agreed to the price hike. They went ignored for two out of the four weeks notice Reddit gave.
Yes, signing a few API users would "increase profit" but not as much as the profit they can (or perceive they can) generate by having control over their platform/clients.
With control they can employ whatever dark patterns they want to extract as much value as they can from ads. Some suggest ads by API but still that's nowhere near the same type of control/guarantee.
Ultimately this even strengthens my point. They want profits above all else. They are choosing the highest potential profit over the less profitable API deal that could be a nice middle ground.
In capitalism it doesn't matter if a better alternative costs a single cent more. If there is a choice, it will be to save that cent.
And I added an edit to point out that if the profit motive was true, they would have accepted the money offered by the API users who agreed to the price hike. They went ignored for two out of the four weeks notice Reddit gave.