AV Receivers dont need a makeover - they need a complete rethink
With all due respect I think some of the comments actually exemplify what is wrong in the thinking about AV receivers. And to some extent that is to be expected from a consumer level. What is less forgiveable is that the same weakness in thinking come from the industry itself.
At this point, the AV receiver does not need a few touchups aka a "makeover" - it needs to be thrown in the fire and reborn.
ONE BOX IS AMPLIFICATION ALL THE WAY TO YOUR EAR
First of all, I think its the wrong path to make excuses about amplification. One could view loudspeaker and amplification as really one cohesive unit of fairly stable technology that should be separated from the signal processing. Put those in the same box. Powered speakers sound better and are more power efficient anyway. Design for this scenario going foreard - and you just injected ooomph in that underused product category, a category that can actually add value for consumers.
These units we can have an expected lifespan of what 10-20 years, maybe more even.
ONE BOX IS SIGNAL PROCESSING
That leaves you with signal processing. Again yes, you cannot keep dragging legacy and heritage around you for comfort and tradition, not any more than you keep your relatives in a box and take them around with you, as worthy as they are.
At this point you want to design a box for here and the future, truth is the content inputs are digital ie HDMI; optical, ethernet, wifi, bluetooth etc. Accept it. You want to have a single headphone out - fine.
I think that leaves you with a digital signal processing box aka AV processor that's about the size of a Mac Mini or Brix Pro.
These units will involve the more rapidly changing technology, so prime useful life here is more like 3-5-maybe tops 7 years?
There are different approaches to this and it is by no means alien. Oppo for example has basically tacked a optical disk player on this device I am speaking of, but sells in in a "standard size" box probably mostly full of air, in order to "look like it is worth the price".
LEGACY INPUTS: MAKE 'EM PAY
You can very well have a receiver in your product lineup that accepts legacy inputs - make that the flagship one and let people pay for the exception, rather than imposing that cost on everyone. For everyone else - sell them a bluetooth adapter for connecting their legacy device to your processor.
INTERFACE INTERFACE INTERFACE
It matters - this is where the rubber hits the road - even before the ears or eyes. You cannot keep cutting corners here and using designers from some school stuck in Tokyo circa 1985.
Yes, its nice to you have an "app". Make it better, make it complete. And no that does not excuse you from having a 21st century worthy small screen and tactile interface on the hardware itself. And the existence of logitech and co does not excuse you from making a high quality remote control that is actually usable in the dark - in full.
CUT OUT THE SILLY MODEL BLOAT
While on that subject we do not need 10-20 models from every maker. That's just a joke and one largely caused by their attempts to distract from the fact that they rehash the same old junk every year with a new "feature". Cost cutting opportunities abound there in product line simplification.
No, I dont expect the "industry", to get this, but then again that is why they are bleeding money, struggling with price points and resorting to cutting past fat to muscle and bone.
CUT THE EXCUSES AND PUT IN THE WORK TO EARN YOUR MONEY
Again some well meaning consumers will excuse these folks, but like I said, it's their JOB to think outside the box and make a better product that consumers didnt even know was possible. That is what gets people shovelling money at you, as opposed to you running perpetual sales and playing airline style games, expect you are doing it not with tickets online, but with hard inventory spead in global retail channels - I mean how insane is that?