I feel like this was inevitable. My very amateurish reading of the strategy goes like this:
Tsipras: A referendum takes the heat off me. If the people vote no, I have an excuse for my creditors. If they vote yes, I have an excuse for my party.
Creditors: To hell with this, we're not even keeping them solvent long enough to decide. Let them see what it's like without our help.
Greek People: Please just feed us and provide basic bank services. Christ.