Well as a scholar I learned there's merit in taking a contrarian position for the purpose of discussion and analysis. I'm not so sure he's "trying as hard as he can" as you would put it, because if he was, then he'd be so confident in his abilities that he'd donate everything
now and the letter would explain to his daughter why he didn't leave her more than a basic trust fund for college expenses rather than millions. Hey if you want to get in line and shake his hand for doing what is, fundamentally, the right thing, then great! More power to you!
But, you know, he could've done all this in private and given her the letter when she turned 16 or 18 or whatever.