It does not specifiy bearing openly. All the 2nd amendment states is that the right to bear arms shall not be infringed.
Just because the ability to legally open carry is not infringed, does not mean that the government therefore has the right to ban concealed carry. Banning either is infringement.
It would be as if the government claimed that they could legally ban newspapers, because they weren't also banning the printing of books, and as long as you have one or the other available, whom are you to complain.
Oh, but they still require that you have a permit to print books. Permits which are issued by the government. But you still have your freedom of the press! All you need is the permission of the government and you can continue to freely print whatever books you wish.
Well, not whatever books. I mean, some books are just too dangerous to allow the average person to print. Those we'll have to ban. But regular "sporting use" books that have no political content are still fine to print. As long as they aren't "assault books" which contain more than 20 pages. I mean, who REALLY needs 20 pages in a book?