A few quick points:
1. Everyone is working off of incomplete information.
2. It is in the interests of all advocates, as long as negotiations are still open (or negotiations can potentially be re-opened) to denounce any compromise as a sell-out that's just too much for their side to accept, in the hopes of moving the final agreement a tick or two or more in their direction.
3. Almost everyone is taking their cue, including the basic information they are getting, from partisans and advocates; see points one and two for where that gets us.
That's not to say that no one is right or wrong about how good a deal anything in particular might be; it's just worth pointing out that the dynamics of the situation should, at this point, leave everyone unhappy.
After the deal is finally enacted, the incentives are a lot more complicated; some partisans may find it in their interest to portray it as a win, and others will not. But at this point, everyone outside of the negotiations should be upset.
Oh, and by the way, Seth Masket is absolutely right.