I guess I fall into this category...I occasionally read with interest some other camera brand reviews...but the thing is that I've never felt that what I am getting out of my Canon is so bad that I just have to change, on the contrary I am generally impressed and have been more than satisfied with the performance of my bodies, lenses and accessories since I went digital with the 20D back in 2004.
Also, I look at the total offering not just the camera body, but also the lenses, accessories and backup etc. For instance in my neck of the woods, Southern Africa, Sony pulled out completely, through lack of sales I imagine, a couple of years ago. They are starting to trickle back but I would not consider buying anything from them at the moment nor in the foreseeable future...Nikon is strong here but their professional lenses are a good deal more expensive than Canon's. And personally I don't like their styling. Fuji is making big inroads here especially among the youth and I like what they have to offer... But it makes no sense to have two different camera systems and they just dont have the selection that Canon has. Also the M6 is considerably cheaper than the equivalent Fuji offerings without even having to go and buy lenses that fit.
Canon makes superb TS lenses and I have the 24TSmk2, which is quite unique imo. So also for the small and cheap 40mm pancake and 50mm stm, and that super compact yet versatile and sharp 70-300L.....and the new 35mm f1.8 RF is probably my next lens... I have a couple of Canon flashes that I hammer in my commercial photography and they just carry on and on. I have not had a body or lens fail on me for 10 years, and before that only once did a lens pack up. I like the way Canons Eos bodies look and the way the menu works. And the reliability, and the familiarity, and the vast options that I can choose from.
On average I keep my body for 4 years and my 6D, which I just enjoyed tremendously has about 100k on the clock and it got replaced by the R which by the way I also enjoy tremendously...so why should I change? Because some, usually anonymous troll, on the internet tells me so, or because DP review gives it 79% and Sony/Nikon gets 89%? And lets say Canons next R is the bees knees and gets 99% rating on DPREview, should I sell everything and go back to Canon only to change a year later when the new Pentax gets a 110% review.....as I said before many of my commercial photographer friends are using old equipment and most of them dont care about the DR, 4K, Fps, Sensor stabilization etc etc.
They just want cameras that work reliably....and my experience tells me that Canon does...
But I am eternally grateful to Sony for pushing the boundaries.....Competition is good for everyone, and if they are fully or even partly responsible for the Eos R happening then all I can say is keep on pushing Sony/Fuji/Leica/Pentax/Olympus!