The thing I find so interesting is his ability to remain such a huge success while behaving so poorly.
I mean...was he able to, though? Don't get me wrong, he had the kind of success that all but a small handful of musicians ever could only dream of. But it's almost entirely predicated upon those two years when he was in his 20s and in a band with--love him or hate him--a guy who went on to become one of the most successful pop musicians of the century. So as with so much other stuff, success is or can be relative and context and perspective are vital. But...
After Cream (and Blind Faith, again with that guy), he had an at best journeyman career. How many copies of his Air Force recordings have been sold this century? What percentage of rock fans have even ever heard of it, never mind actually heard it?
He did some work with PIL which was cool.
He got to play with Fela Kuti, which is beyond cool.
He had a trio with Charlie Haden and Bill Frisell, which blows my mind.
But you'll notice that all these, and his other projects, rarely lasted more than 18 months, if that. For
51 years after Cream broke up, the guy couldn't find anyone to play with for more than a year or two at most. And, as you said, given his monstrous talent, that's not what I'd call a huge success.
Again, I'm just some dude on the internet who hasn't even played in a bar in decades, and he was world-famous. He had a documentary made about him. Famous drummers sang his praises. And anyone who had the kind of success Cream had for even that brief period's got nothing more to prove.
Except it sure seems like, looking at his career, he kept trying to capture that kind of magic again and never came even remotely close. And you know what? Looking at the level of talent with whom he played? I'm pretty sure that it's because he behaved so poorly. Because he was such a total jerk.
I obviously have no way of really knowing, but I'd be very surprised if in his best year after 1970, say, other than the brief Cream reunion, he ever made half of what, say, Steve Gadd or Jeff Porcaro or Vinnie Colaiuta or Simon Phillips or Jim Keltner or Kenny Aronoff made in their worst year.
What's the matter with people who expected him to act " normal " ?
I don't know that anyone ever expected him to act "normal." I think most people who knew anything about him whatsoever knew that was an unrealistic ask. But I also think most people expect most people to simply not act like a complete and total jerk. And more than his command of polyrhythms or whatever, that was absolutely his defining characteristic.
He wanted to be left alone didn't care for journalists or the straight world they represented . He wasn't a pseudo bad boy , he was the real thing ,people can't handle that . He let his drums do the talking and they told a fascinating story .
As the song goes, you say
tomato, I say
complete and total jerk.
I'm guessing Ginger may have been a little bit like this. Among close friends and family, he may have been a different guy.
That would be nice. But--and I'm not claiming to be any kind of expert, I've read and watched the same stuff that most of us have--there seems to be little to no actual evidence for that, and oh so much very much to the contrary.
People are complex. And no one knows the struggles others are going through. But as Maya Angelou said, "When people show you who they are, believe them the first time." From all available evidence, I think Ginger would have been unhappy about attempts to portray him as simply a tortured or misunderstood soul. I think he liked having the reputation of a complete and total jerk. Goodness knows his behavior suggests it.
Musicians with difficult personalities don't usually last long. I'd say maybe 6 months to a year. 
