Hey, I know for desperately wanting to find ways to forgive an artist for being weirdly inconsiderate and out-of-touch about things late in the game because I love his or her early work and because I was on what I came in near to the ground floor of the fandom, wombles.
There is a deep feeling of wanting to forgive for the good times and the ways it felt like you were along for the ride of the good times, you almost don't wanna sully those memories by admitting where we are now. I have been there.
But Onstad's lack of consideration, lack of grace, lack of any kind of admission that anyone had anything to do with the positive parts of his success and accusation that the bad parts are everyone else's fault... man, it sucks. It is a shitty way to treat thousands of people who elevated his hobby into a full time job that would be a dream job to millions and The Dream Job to thousands, no matter how inconvinent he has found the other side of that sword.
Dude didn't have Hephaestus crack him on the noggin one day with a magic hammer and then Achewood was standing out there in the sea on the half-shell with a Dark hoss comics deal and Hollywood option rights and thousands of people paying forty dollars a year to look at his cocktail napkins. A lot of True Believers and boosters picked up his hobby-work, fell in love with it and took him there.
If he wants to stop doing Achewood for now or forever, if he HAS to stop doing Achewood now or forever, that's totally between him and his muse if he has one.
But to be so rude and accusatory and ungrateful and blind in the way he handles it, there's no set of artist's rights that forgives that kinda mistreatment.