With time having run out the Republicans took what they could get. The court came out one way by abusing its discretion against existing law. A majority, but not a sufficient majority to get past procedural hurdles, wanted to correct the court. So there was no choice but to pass a swiss cheese bill and hope it influenced the courts, which it did not. The executive has been the obsequious boot-licker of the courts for so long (since sometime between Andrew Jackson telling the court to stick in 1832 and Dred Scot in 1857 at least) that 90% of the people think it's supposed to be.
I disagree - if the court has discretion to decide one way, they surely have discretion to decide the other way, else it's not "discretion" at all. Nevertheless, IMO, congresscritters simply did what they always do - pose for the cameras and punt to the courts, attempting to absolve themselves of any responsibility for effective action in the process.