Was Jobs selfish? Or did he just not use his charitable giving as a means of self promotion or legacy building? Fair question. We're assuming facts not in evidence.
I definitely don't see what Gates and Buffet are doing as "legacy building" - if they wanted to build a "legacy", they would create some self sustaining "family foundation" that acted more like a social club than a charity. Instead, they are explicitly stating they want to give most of their money away while they are alive and all of it shortly thereafter.
I don't know what Jobs did with his money. I'm criticising his values, as described in this statement that clearly paints philanthropy as beneath him, to those of Cook. Maybe he gave money away even though he thought it was beneath him, but it's still disgraceful and loathsome to paint philanthropy as a pursuit of the small-minded.