I think a good question is what happened to the upper/pro-sumer/pro Canon dSLR & lens market - in which probably the greater population of the site visitors here encompass? There doesn't appear to be any stagnant slowing of product releases from rivals like Nikon/Sony and third party lens like Sigma and Tamron.
One dual pixal innovation on a 70d with a whole collective of marginal "innovations" of rebels, kit lens upgrades (basically slapping the STM label on), and garbage powershots aren't cutting it for this past year+.
If Canon is keeping tight its R&D spending on marginal rebel/kit upgrades why is it blowing $$$ on releasing lenses like the 24-70 f/4 is L, 24 2.8 IS, and 28 2.8 is? I blame part of the drop in those graphs/numbers on failed business decisions from Canon.
Since 2012-today, the only worthwhile "pro-sumer/pro" lenses have been the 24-70 2.8 II and 200-400 f4 1.4x.
One can only hope with Canon these past few years, that they enter the medium format market or do something more dramatic.
I don't think that it's just Canon, I would accuse Nikon of doing similar. The only manufacturers that have been churning out the camera and lens releases over the past few have been Sony (E & FE-mount only
), Fuji and m4/3rds. Of course, these manufacturers have needed to build there systems from scratch, whereas Canon and Nikon have a comprehensive system built up over years. Of course, one could make the "look where it's got them" argument: Sony are in the red, Olympus are all but bankrupt with shareholders demanding divestment of the camera division, and Panasonic stills cameras are effectively in the "last chance saloon" with their new Chief Executive threatening to sell any under-performing business unit.
I would tend to agree with Thom Hogan that where the "big two" are weak is in their support for their APS-C lines. Unless they are planning to release full frame bodies at "Rebel" prices (which isn't going to happen any time soon, if ever), their EF-S/DX lens line-up is seriously weak at the wide angle end. I can only think that they hope this drives "serious" users to go full frame, but the danger is that they go mirrorless instead; this is especially so because the sort of user that wants fast wide glass (where X-mount and m4/3rds excel), is also the sort of user that can live without phase detect af.
The other danger is the third party lens makers are starting to encroach upon their turf with higher end enthusiast and professional lenses; these have traditionally been a good profit generator for Canon and Nikon.