Maybe because it would drive all those JPG shooters into desperation not being able to reach their setting parameters if they had inadvertently selected RAW only?
FujiFilm X100, Fuji X-Pro 1, Konica Hexar RF, Hexanon & CV glass & Nikon Coolscan V ... plus a big, bad DSLR
My RFF Gallery
, My Flickr
, My Ipernity
, all presenting different bodies of work