That's not how the Supreme Court works. They are selective about the cases they hear. Especially looking at a 6-3 ruling with this court it's clear to see this was an ideological selection.
Yes, the case was appealed to the Supreme Court who chose to hear it instead of choosing not to hear it. That is ultimately why they ruled on the case.
Given that, it really does seem that the court ruled 6-3 in favor of the plaintiffs who are trying to draw a line around gay couples because the court is trying to draw a line around gay couples.