canon sold less DSLR's during film then they do now.
also;
you get 0 sales and 0 profits when customers pick up and go to Sony or Fuji.
While profits are good, sales are also very much something stockholders look at. as well as marketshare.
I know. But back then they could intercept some of those sales with their P&S cameras, while now they are not in the phone market. And back in the film days it was a very different market, with film and development costs being part of users' expenses - which confined photography to a few "special events" for many, and mistakes were "expensive" - and the complexity higher. That put SLRs in a more narrow market. It's no surprise it was automated models like the Canon AE-1 to start bringing the SLR "to the masses", but mostly digital later, which removed the film and development costs, and allowed for correcting mistakes earlier.
In the past years they got used and built manufacturing capacity for a larger market - which now is shrinking, so they have to plan for it. The extensive range of many different models, mounts and lenses looks too expensive for the future. I'm not surprised they are looking for a costs-saving strategy.
I'm not saying this is the right strategy. I'm just saying from a manufacturing point of view they could see a single mount and more shared components a less risky way to plan for future models, while reducing costs. That strategy may win them more customers, lose some of them, or just keep the status quo. That all depends on what lenses and cameras they will deliver. and how they are accepted.
A mirrorless mount, even with a larger diameter that means not-so-small cameras allows for "rangefinder-like" lenses that can be both small and good - even for a full frame sensor - is Canon going to deliver them now? The RF lenses I saw till now are a different league - not good for a small compact camera.
Of course that would be a specific investment for a market segment that may not be large enough to repay it. Maybe they will go towards a less risky path, trying to deliver something they think should appeal the lower-end market, looking for a small camera with a kit zoom and little else. Just, IMHO that's the market phone makers aim too, especially since camera features are now among the few differentiating features among phone models, trying to justify their high prices. And they now have the fashion trends on their side, and the need to "publish immediately, who cares about careful culling and post-processing?"
That said, I liked the M line. I planned to buy a M5 MkII because I could not buy an M5 earlier, life events forbade me to invest money into a different system in the past two years and a half. Now it looks I should feel happy I didn't. Maybe Canon is overlooking a good niche market that will be occupied by the likes of Fuji, maybe that market won't exists in a few years. Maybe I'll get a view camera, eventually....