Sandmonkey is highly principled. That is good for his self-image, but might be bad for Egyptian reform in general. The thing is, if Mubarak can’t reach a compromise with liberal forces he will seek one with the Brotherhood. And any compromise that the Brotherhood accepts entails them eventually reaching power and suppressing everyone else.
The trick is to compel Mubarak to reach a compromise that makes him yield most executive authority to representatives of the liberals. That means liberals spending a lot more time in Tahrir square, both protesting and organizing to select leaders in the safety of the crowd that also represents the crowd.
Finally, liberal forces have an important matter to consider: what will they do when and if they are confronted by violence or the threat of violence from forces of the Muslim Brotherhood? Will they cave? Run? Or will they fight back? And if they are unwilling to cave or run or fight back yet still want to see an Egypt not ruled by an Islamist regime, don’t they have to keep a Mubarak handy, at least temporarily, and what is it necessary for him to do? What will they offer him in exchange? link