And there were reasonable arguments on both sides. And there were 2 dissents and 1 concurrence filed, so even within the Court, there were different interpretations, even among Justices who agreed (on each side).

No, I don't believe any argument that burning a flag isn't protected speech is reasonable.

Well then you have 4 supreme court justices you need to argue with. What is the law of the land and what is moral don't always line up. All we get is the hope that our system tends toward morality over time.

I don't need to argue with them because flag burning is already protected speech and the justices are all dead by now.

Nearly 40 years later, it may seem to be a settled question.

But then we have Roe, which was settled, until it wasn't.