SCOTUS is indeed limited to the question raised during the appeals process. Even if SCOTUS thought "geez this patent sucks," they can't do anything.
Why not? Well, for better or worse, the American judicial system puts a lot of weight on trial courts and juries' ability to assess facts. The appeals system was set up in such a way to prevent higher courts from actually deciding the case. If SCTOUS had found that the lower courts applied the wrong rule of evidence (burden of proof here), then the case would have gone back to trial and retried (isn't that crazy?).
And trust me, law school doesn't quality everyone as a guru. I have some experience with appeals, but I'm far from an issue & appeals lawyer (they're pros at this). So, take my words with a grain of salt.
Why not? Well, for better or worse, the American judicial system puts a lot of weight on trial courts and juries' ability to assess facts. The appeals system was set up in such a way to prevent higher courts from actually deciding the case. If SCTOUS had found that the lower courts applied the wrong rule of evidence (burden of proof here), then the case would have gone back to trial and retried (isn't that crazy?).
And trust me, law school doesn't quality everyone as a guru. I have some experience with appeals, but I'm far from an issue & appeals lawyer (they're pros at this). So, take my words with a grain of salt.