Because the Snr Officers in the RAF view RW as their dirty little secret that they'd really rather not have to mess about with. Far better if it's all kept in a dark corner.
Yep, that's the official line. (Inspector of Flight Safety - CHART report Aug 1992 "Chinook is the Cinderella fleet of the RAF"). Not a lot changes. Although it has to be said Cinderella popped up again in the Hercules report of 1998 (HEART) so perhaps RW and Transport are both dirty little secrets!