“This could be a case which ultimately goes to the Supreme Court, and have that Court decide there is indeed a constitutional right to homosexual marriage.”
Roberts and Scalia and the older liberals probably thought this would be politically unacceptable for too many people after giving the homos everything they wanted on the DOMA case. They also knew that they did not have the votes to rule Prop 8 was valid so they punted with the standing argument.
Kennedy wrote the dissent on the standing issue. But the leftists knew that they could take this up later and get their ruling.
I disagree - They didn't punt; they repudiated the power (and much legitimacy) of the CA supreme court. You see, they denied standing that the CA supreme court had recognized.