I think there is a genuine concern that Canon sensors are no long competitive and are a generation or two behind Sony and Nikon (same sensor). There is some minor gripping about this and that feature or mirroless offerings but the real complaint is the sensor. When Canon had the best sensors (a long run) the Nikon fan sites were awash with similar complaints on their sites and the fanboys saying things like "12MP is all you ever need". Same thing you are seeing now on this site. The fanboys are saying things like "18MP is all you need". "I would never buy a camera with than many mega pixels", or "It's the glass, yeah, thats why I stay with Canon" ignoring the fact that Nikon has equally fine glass and Sony shooters have access to better stuff. If Canon catches up the same old fanboys will be lining up to buy the best stuff and crowing about how important the big sensors are.I think some of the Canon commenters should feel a bit vindicated by the fact that Nikon just dialed back the MP in their latest FF camera to 24. They must have had some reason for doing that. It wasn't to save money as the sensor will be the same parts cost. I suspect that there were plenty of Nikon users that really had no use for 36 MP. I think they wanted to put something closer to the 5DIII.
Nikon dialed back nothing. Did they take their 36mp sensor off the market??? They used a cheaper (but better than Canon) sensor so they would not compete against the 820D. They built a camera at a price point (cheaper than Canon, more MP) so as not to cannibalize a market they already serve. Nikon gives their customers a choice of FF sensors "36mm? yeah, we have that..... will 24 do? Sure, we have that too". Canon (18, or 20 or 22....want more? we don't have it and you don't need it....BTW we have better glass). I will not stop saying it. The most important component of a camera is the sensor. Canon sensors are not as good as Nikon and Sony sensors. CANON!! WE WANT BETTER SENSORS!!!! WE WANT WHAT NIKON AND SONY HAVE!!!!
That 24 MP sensor isn't any cheaper than the 36 MP one -- same technology, same wafer cost, same yield, same number of die per wafer -- that's how it works. They put a 24 MP camera on the market because there was demand for better performance in terms of something other than the MP number. I expect that a sufficient number of Nikon users wanted smaller file size and the 62% higher firing rate that comes with it.
As for your last comment, that about sums it up as far as I am concerned. We want it because Nikon and Sony have it. Nothing to do with better photography or any semblance of real practical need. It is all about feature envy from what I can tell. Here is a clue for you: As long as all you do is bellyache on camera forums, Canon needs to take no action. Nikon and Sony apparently make what you want so sell all your stuff and go buy what they make. If more of you mindless whiners did that (instead of all the mindless whining and forum trolling), you would [probably see more action from Canon -- money talks.