After this day, I think the most likely answer to this question is: because they can!
The fine words and apologies we heard early on last year when the whole mess started, those were all just appeasement. They meant nothing. Empty slogans, uttered to calm down uproar, never intended to be lived up to.
The company can do that because the community has no way to inflict true pressure on the company. We agree with them, love their work ... we put in more volunteer work, they make more profit. We disagree, we plea, we stop, ... seems to not matter enough.
The other day I saw a post on quora.com where a top writer announced to stop writing (to protest the insane Quora partner program). Guess what: many other top writers chimed in.
Unless you magically convince 50 to 100 of the top writers on Stack Overflow to do something like that, the most realistic answer is: SE Inc will continue to act like this. And we can still only complain and walk away or not. It doesn't make any difference.
