I think Bill Gates was every bit as ruthless as Jobs was. But Bill had his enormous success earlier in life, stepped down from his company earlier, and was thus ahead. Despite being the same age, they were in very different stages of life, career, and success.
Who's to say that Jobs wouldn't have gone into philanthropy once he had stepped down from Apple, had he not been a (relatively) late bloomer and died at a (relatively) young age? Then again, maybe he wouldn't have. But I think it's unfair to lambast Jobs for not living long enough to reach that stage of his life.
There is one possible signal that Jobs wouldn't have chosen to go into philanthropy: He never reinstated Apple's charitable gift-matching program after terminating it during Apple's darkest days. Instead, that turned out to be one of the first things Tim Cook did.
Obviously this is a very limited data point. We know very little about the context around those decisions (e.g. were there external factors that took some time to sort out? did they decide to do it and then deliberately hold back until Tim Cook took over?, etc.). Nevertheless, it is one of the few data points we have on this question.
Gates' parents apparently thought he did not do enough philanthropy earlier on, and Gates was also facing mounting calls from people about it in public long before he started his efforts.
While I don't have much love for either of them, people can and often do change with age. Gates appears to have changed a lot - perhaps Jobs would've eventually too.
Who's to say that Jobs wouldn't have gone into philanthropy once he had stepped down from Apple, had he not been a (relatively) late bloomer and died at a (relatively) young age? Then again, maybe he wouldn't have. But I think it's unfair to lambast Jobs for not living long enough to reach that stage of his life.