Is there a reason you can't get write access to a drawing  file that was opened read-only?

I noticed that when I open a drawing file as read-only, there's no option to get write access like there is for every other type of SolidWorks file.  I realize I can just save the file and overwrite what's there, but the same could be done for every other type of file.  This isn't a big problem, but the inconsistency is odd.  It makes me think I may be overlooking a setting or something.