It's neither arrogance or immaturity, it's frustration.
They're not obligated to build the perfect camera but if they want to continue to sell cameras in a shrinking market with sharper competition then they need to address the specific requirements of discerning users.
I'm still using a 1DX and 1DS3 because Canon have failed to produce anything compelling enough for me to buy in the past nine years. Looks like that will continue for another generation.
If Canon or anyone else wants our money they have to damn well earn it. That's not entitlement, that's the market.
The pre-order success shows that Canon understands the market very well. However, by your argument, delivered as if it is fact ("that's the market.") Canon should be struggling right now for failing to impress "discerning" customers. What is discerning about complaining about a company not building a product to your exact desires? What specific things are missing from these cameras that displeases you, yet you are doing fine with your 1DX and 1DS3? Maybe something is lost in text communication here, but to be frank it sounds a lot like complaining just to complain to me. There seems to be a growing amount of this lately- people pointing out everything wrong, every way they are being victimized or denied some opportunity and what they should be getting- that behavior is what people are labeling entitlement, and I agree with them. Placing opinions and emotions over the compromise required of reality is a form of entitlement. I'm always all ears for a rational critique or well presented frustration, but that comes with some logical reasoning, not just emotion and opinion.
Your words (Canon have failed to produce anything compelling....they better damn well earn it...) suggests you take this somewhat personally but I can't relate to those vague complaints or the emotion. To me and many others Canon have been making great cameras and lenses at many price points all along. I still shoot with a 100-400 mm Mk1, and I'm certainly not mad at Canon that the updates to the lens don't justify the price of a new one to me. Why bother if I am happy where I am at?
How is it you are working fine with older cameras instead of switching brands if the grass is so much greener with all the competition? You imply Canon is failing to compete, so it begs the question.... Or has no company impressed you and you are just upset in general, waiting for some perfect camera for a custom price? Life is short, love what you have or move along if you've found something better. Why be unhappy? You could contact Canon or these other companies directly, which is sure to be more effective in making them consider changing to your needs.