I’m not an expert in this, but I think the concept of a “great man of history” is controversial in the sense that some people think great men of history simply

I’m not an expert in this, but I think the concept of a “great man of history” is controversial in the sense that some people think great men of history simply don’t exist; that history follows a specific path for reasons beyond individual control. In this case, one would argue that if Linus Torvalds didn’t do what he did, someone else would have and the world would be mostly the same. It’s hard to be sure about these counterfactuals and I think for most “Great Men of History” you could make the same generic argument. However, Linus did do it, so I guess whether he’s a Great Man of History depends on whether you accept the Great Men of History theory in general. On the other hand, if you’re stingy enough to say that someone can’t be a Great Man of History unless you can definitely show that no one else in their place would have done the same thing, then I think some people have a stronger case than him. For instance, to my understanding, Winston Churchill was notorious prior to WWII for being an incorrigible warmonger who wasn’t willing to be “reasonable” about Nazi Germany. I think it’s likely that without him, whoever else was PM would have sued for peace after the fall of France. After all, you could name most of the people who probably would have been PM at the time, and as I recall, most of them did want to sue for peace at that time. I don’t want to get into a tangential debate about Churchill here—“Great Man of History” refers to magnitude of impact and not moral goodness. My point is, Churchill is the kind of person you point to as strong evidence for the theory of Great Men of History in the first place. Linus doesn’t have that strong of a case.