What did the guy do that deserved "getting his head ripped off?"
I assume you watched the video. He was asked to stop harrassing Aldrin. He didn't. He continued to insult him close up. He asked for the punch out, he deserved it.
I think that had most of us been in Mr. Aldrin's position, with a wacko practically spitting in our face, we'd have done the same thing.
There were concepts before your time called honor and integrity. These concepts, while foreign to many in this more enlightened age, are held dear by many in previous generations.
When a man’s honor or integrity were questioned it was a given that a MAN would have the right to defend those characteristics, at times forcefully.
If a man did something dishonorable, he was worthy of scorn from his peers and marginalized by society. Again, a foreign concept (scoundrels are held in high regard in this age).