True, and Canon is a conservative company that's renowned for being slow to change. But business models sometimes have to change to reflect new market conditions.Hmm, me thinks you don't know Canon. They have never done high volume 'loss leaders' the loss leaders have been super exotic headline lenses like the 50 f1.0 and the 200 f1.8. Don't forget for years the Rebels and entry level kits were the cash cows of the camera industry and very few people who purchase entry level kits buy anything else.
I believe Canon makes most of its money from selling lenses, rather than camera bodies, and in order to sell those lenses they need to get people to commit to the new mount. To do that, they need to attract novices to RF, so they need to release at least one cheap RF body.
Canon needs a full set of RF gear ranging from cheap-as-possible bodies and kit lenses, through the enthusiast middle ground, up to the exotic and expensive pro equipment. It makes a whole lot more sense to base all of these cameras on a single mount, in terms of design, manufacturing and progressing users along the upgrade path.