Of COURSE Stanford didn’t have any responsibility for his brother
He wasn’t obligated to help Stanley out because he had no idea Stan was in a bad place, presumably because Stan never told him, so we can’t blame him for not “helping out” for ten years
But asking for his bro after ten years only for a favor, and not once considering just how much Stan loves him, well
There’s your sterling character flaw right there
And he was completely right to say Stanley ruined his own life
But it was still pretty shitty of him not to even try defending his brother after his brother had been doing just that for years, plus (apparently) never trying to contact him after the fact
As for the whole “not being grateful when Stan brought him back” biz well
We don’t know what went on in that dimension
So I’m not gonna pass judgment of Stanford for that as of yet