He IS smart, and you can include academics in that. By the time he dropped out of Harvard he'd taken some challenging graduate courses, and of course he had business efforts at the same time. On the other hand, I taught a guy who took three different challenging grad courses at Harvard as a sophomore, and while he was certainly .01% smart, he hasn't changed the world much in later life. (I think he went to work at IBM Research and didn't do anything particularly noteworthy.)
Bill is said to be a very good coder but not a great one, by people in a position to judge.
I can hold my own in discussions with Bill, but I can't blow him away, and I've had IQ scores a lot higher than 160. I haven't changed the world much more than my aforementioned student has.
Like most successful tech entrepreneurs, Bill at various times has believed his own marketing too completely, leading him to say erroneous things.
Bottom line: Bill deserves to have his opinions listened to on any subject to which he's given a lot of thought. But that doesn't mean they're actually correct.