Sometimes you want to manage your sounds (especially if you are creative and make your own). Sometimes you don’t need big brother telling you what patches and waves you must have in your library.
Yes, of course there must be a delete button. And apparently it isn’t possible to change the category of a certain preset. And you can’t delete categories or create new categories.
Simply set the Location to User Content, then you won’t have any more trouble with big brother. (p. 522 english language manual)