Because of the wide differences of positions between Greece and its creditors, positions are hardened by the respective electorates, which provide little room for maneuvre.
Therefore, any outcome of the negotiations will likely be a fudge that allows both parties to save face and face less wrath of their electorates.
However, a fudge is dangerous in itself to improve the Greek economy; clarity is needed to take away the uncertainty.
The room for a fudge seems fairly small, and there are plenty of banana peels on the way that could derail the whole process into an accidental Grexit.
A Grexit itself is likely to be a catastrophe, and isn’t priced in at all.