The attitude displayed was definitely dickish (I don’t want to read this thing! What ruling will be the least effort?), but whether it will actually lead to a dickish ruling I cannot say.
I said it might be warranted
I guess it depends on the intent and nature of the ruling. You could conceivably have two rulings which are effectively the same legally, but still send a different message. For example one says “we are narrowly ruling out of prudence” and the other says “not our problem dudes, clean up your own mess”.
And while I understand the benefits of a narrow ruling, and avoiding the appearance of an activist court, some cases were brought to court not just to determine the particular matter at hand, but also to serve as a guideline to future legislation. If the court just rules on some nitpicky technical thing that is only relevant to that case, and say nothing at all about the larger issue, then it wastes the time of the nation guessing at how to properly legislate the issue, and then dragging the new version all the way up to court again.
It’s fine if they throw it back to congress, but it should be with some clear useful notes.