Why is my uncle so unsatisfied?

They have 3 kids that ALL grew up. They are 29,28, and 26. The oldest one got a GED and is barely making enough to stay afloat. The other dropped out of High school and wound up in jail for drug abuse. Now the third one went to grad school and became a Lawyer. He does very well, makes a nice living, and by his firm's raise chart, he will make 6 figures when he is 35. My uncle feels like he failed as a parent, since my aunt died 2 years ago from alcohol. he went broke fueling her addiction, and was also giving my cousin drug money. Now they ALL live with Geoff(lawyer), and he cannot start a family while trying to support his dad and siblings. My uncle has now turned his anger toward Geoff, saying that he should have done more to 'compensate' for the other two. i think that is ridiculous, and i want somebody to explain why he would feel like that