Why should it not? For the most part this flag seems to be working. And it improves security. Windows can't do something like that for most of the software targ

Why should it not? For the most part this flag seems to be working. And it improves security. Windows can't do something like that for most of the software targeting it because it's all in binary form. For the software available through the default Ubuntu repos, source is available, so Ubuntu can offer this.