My grandfather died. How should I feel about this?

My grandfather died recently at 96 yrs. He was stepfather to my father and he had two living step-daughters (my father’s sisters). He was a very personal man and mostly kept to himself. His wife, my father’s biological mother, died about 5 yrs. ago. My father, died about 20 yrs. ago at 56 yrs. of age. My father had a good relationship with his mother, stepfather, and sisters. They were all fairly close. After my father died, my sister and I kept in touch with our aunts (my father’s sisters) and also my grandmother (until she died five years ago) and my grandfather. After my grandmother died, my grandfather became even more private, but used one of my aunts as a conduit for relating with the broader family. We would have dinner with him occasionally and have him to our home on holidays. Upon his death we (my sister and I) and the two aunts, met with his attorney to review his Will and Living Trust. The attorney instructed us to turn to the last page of the Trust and see the most recent changes to the allocations. There it showed my two aunts are to receive roughly 32% each of his estate, the remaining 32% went to a wealthy nephew, and 2.5% goes to my mother (my grandfather’s daughter in law—and my father’s wife). My mother has always had a fine relationship with my father’s parents. They weren’t especially close but the relationship was friendly. My sister and I weren’t expecting to receive anything but we were a little stunned to see our mother received so so little. We don’t know exactly how much money is in the estate because there is a small (but very profitable) business to sell, but my estimate is it is quite a large sum of money. As may father’s only son, I feel terrible. I feel like not only did I lose my father at a young age, but his sisters and stepfather just discarded him and his relatives—my mother, my own family and my young children, and my sister’s family and children. None of us are well off. We’re not poor but we struggle like most people. The money aside, I just feel lousy. It feels like such an affront to the memory of my father, who was such a kind and good man. As his son, I feel I should say something. What do you think?