Furthermore, his leadership qualities depend only on his ability to lead a group towards a goal, which he was doing swell at.
It sounds like his behavior was alienating people who would have been willing to work toward that shared goal, but were instead pushed away. So based on what I'm reading, he was a poor leader in this regard.
The few I've seen mentioned seemed a bit fragile and easily upset to be suitable for doing reasoned public advocacy.
I almost feel sorry for him-- like maybe if he had someone who could just tell him: "Dude, Slow your roll!" he would not have gotten into this situation.
On the other hand, he's an adult, old and wise enough to know better, especially as a spokesperson and thought-leader. He did it to himself.
Reasonable is subjective.
In practice, the "reasonable person" standard is achieved by asking a jury. In a jury, the members apply their life experiences to the case they're deciding and then persuade each other to reach a unanimous conclusion. That's an entirely subjective process, and if you repeat it with another jury you can get the polar opposite answer.
I think that almost all juries could agree on some subset of behaviors being labeled as “horrible.”