Joe (and many of us for that matter) sees himself as an elite player. As has been pointed out, the elite teams are served excellently by top level keepers so I don't buy into the argument that dropping Joe will lead to him seeking a transfer. I also think Joe is above that. There are very good goalies such as Begovic, Guzan and Ruddy who are not playing for the best teams and who have the capacity to develop further by stepping up a level. In short, the market does not favour Joe.
The reality is that Hart needs to realise that he cannot make basic errors with impunity, nor is he outside the loop when it comes to rotation. He is a very good keeper and I hope he is a big enough man not to throw any toys out of the pram. Pantillimon deserves his chance and should play until his form dictates otherwise. The problem is that a "Little Englander" mentality will be adopted by sections of the media, the same hacks who revelled in trying to dismantle Hart's reputation over the past weeks.
I suspect that Joe has the mentality, maturity and talent to overcome his current tribulations. Pellegrini is caught between a rock and a hard place. He has made the call it seems - either way required courage. In the final analysis, we all support the team irrespective of the personnel. We'll all disagree about who should play and whether the right decisions have been made, but that's why we have Bluemoon. Very good arguments from both perspectives have been made in this thread by the way.