The counter argument is that if one does not change any hidden options from it's default value, you don't need to know what they are set to and hence they are not visible.
That's true execpt when it's not. Hidden options don't help manage a filer. When something is wrong you need to make sure of the settings and in the case of the recently discussed cifs.nfs_root_ignore_acl option you don't get full function of software you paid to use if you don't know the option exists. Either way I don't see a benefit of hiding function.
-Michael Cerda