Ideally, both sides would lay out their maximalist positions, and then they would negotiate the differences. What anvi is arguing here is that Obama should be willing to negotiate the differences if the GOP negotiates as well. But what people are complaining about right now is a different problem, which is the apparent reluctance of the GOP leadership to detail their maximalist position (because entitlement cuts are unpopular). So how do you start negotiating before you're clear about what you're negotiating over?
To be clear though, while the GOP leadership doesn't seem to be spelling out specifics, some individual members are going rogue, and offering their own entitlement reform proposals:
http://www.washingtonpost.com/opinions/sen-bob-corker-a-plan-to-dodge-the-fiscal-cliff/2012/11/25/0e237712-3586-11e2-9cfa-e41bac906cc9_story.htmlAs Jan. 1 gets closer, perhaps the GOP leadership will adopt elements of that plan as their own position? I don't know. I guess we'll find out.