Why not? They are all celebrities. Celebrity status is not really correlated to the actual work they do [although some work requires some notoriety]. Gordon Ramsey's a restaurant owner and chef but he's also been on reality TV. Malala became internationally famous for being the target of an assassination plot, not her years of advocacy for women's education beforehand.

as a simple comparison: would Harold (of "hide the pain" fame) be considered a celebrity? what about Linus Torvald, or heck: Linus Sebastian?

I'm simply curious, I don't really know what line we have between what is "local icon" and when we call someone "celebrity".