The criticism section looks okay to me, it seems to mention both the criticism and its counterpoint for most of the points it maes, although it really really needs some cites. Whether or not other articles have criticism sections is fairly irrelevent to this one: either the criticism in this article is fair or it is not, tit-for-tat is not a valid reason to change it. Of course, if you do feel there is sufficient criticism of Ubuntu to warrant a section, feel free to add it to the article. .