Jada would have punched him but that dress meant she couldn't walk up there lol
While I TOTALLY understand why Will and Jada would be upset about it, it isn't something to joke about and is obviously a sensitive subject to them. I have a friend at work who has alopecia too, but she doesn't let it keep her from being who she is. It represents a much larger issue for a public figure though.
On the other side of that, if everyone went after every comedian who made a joke about them, because it is nothing more than that, we'd have a lot of dead comedians. It was the wrong way to handle it, especially in front of a full house and millions of viewers on TV.