Here I'll weigh in. Working with groups like Public Knowledge and EFF in killing SOPA, we were going to lose the Senate on PIPA until the President weighed in. We heard from Senate staffers who felt there was an arrangement between the parties until the President (through IP staffer Victoria Espinal) put out his statement.
The White House letter, as murky and contradictory as it was, represented a clear break with its previous unequivocal support for the MPAA/RIAA position.
What does whether or not a petition is responded to have to do with open-sourcing code in a White House repo? Your complaint is like if Mac open sourced a component of OS X and you went on a rant about them not moving work out of abusive factories in China due to a petition.
True, but it's hard to disentangle the product from the thing that produced it. If Apple open sourced a product, I would fully expect to see criticism of their policies (probably around openness and and transparency, rather than labour) in any collective reaction.
The White House letter, as murky and contradictory as it was, represented a clear break with its previous unequivocal support for the MPAA/RIAA position.