I just think he is consumed with bitterness, jealousy and resentment.
Even the title of his book is indicative of this.
It's very sad for everyone and he should surely be thankful and relieved that he has been spared the burden that his brother faces.
I didn't blame him at all for leaving all that behind but he has sought publicity at every turn, not for his causes but for himself.
He needs to take a big step back, go for therapy and learn to be happy for everything he does have in life. He found a woman who loves him, has two lovely children, plenty of money, thanks to his "awful" family, a home and choices.
So many people in this world would be thankful for a tenth of what he has.
I know that is not easy if he does have severe MH problems but this is not helping him to achieve health. He can afford private therapy from a reputable practitioner but even that, it seems, has to be in the public domain. If anyone wants to pay.
He is his own worst enemy.