In order for people to take advantage of USB type 3, they have to buy things (adapters or new hardware).
In order for people to take advantage of thunderbolt, they have to buy things (adapters or new hardware).
Etc.
What's the difference? My point is that people (apparently like you) who are happy with 1080p could still enjoy their 1080p to the fullest. This would have ZERO effect on you. You could buy a 4K set when your 1080p conks... or stick with 1080p then (if they are even still available then). However, a 4K

TV would give people who are not you a path to get more out of
THEIR 4K sets.
I'm happy for you that you find 1080p optimal for now. That's wonderful. Other people who are not you feel differently than you. They could get their wants met too. Apple could sell them

TVs too. So you could "win", they could "win" and Apple could "win".
"Too expensive" is ambiguous. There is OLED 1080p sets too. There are reference quality 1080p sets too. One might consider them "too expensive". Is that an OLED screen in that 5K iMac? No? So is that unable to deliver (another ambiguous, eye-of-the-beholder term like) "cinematic quality"? Are those OLED screens in retina iPhone 6, iPad airs? Is all that junk?
Let me guess: all that "is different". It's not junk screens when Apple has chosen those for their currently-available technology but unless 4K (but not 1080p) screens are OLED, one cannot get a "cinematic quality" experience without enduring a "too expensive" outlay of cash.
So CDs were out en masse before we could get CD player hardware? Blu Ray discs were out en masse before we could get BD player hardware? 720p videos were abundantly available in the iTunes store before there was a 720p

TV? 1080p videos were abundantly available in the iTunes store before there was a 1080p

TV?
I'm looking through the iOS app store for apps that will utilize unique features only available in the A9 and A10 chips. Where are those apps? I'm looking through the Mac app store for apps that will utilize the unique features built into Intel chips coming out in 2018. Where are those apps?
But this (one) time, it should be different... the software should be out en masse BEFORE there is hardware availability to actually play it.
There you go. Why bother ever shooting any event in 4K when you have the capability? Apparently some events are important enough to you to capture at a level of quality beyond what you can play back on your TV now. Guess what happens in a few years where you can get your "cinematic quality" 4K TV without it being "too expensive" because you waited long enough? That video you shot at 4K will then dazzle.
Why do we have the cameras in our iDevices that shoot beyond what can be displayed on any Mac or 4K screens available now? Why aren't you railing against Apple for the uselessness of putting cameras in iDevices that can shoot at higher resolutions than what can be displayed on any screen we have now? Again, let me guess: "that's different."
Huge hard drives are CHEAP. I'd shoot everything that might matter even a little to me in the future (especially home movies you'll never get to go back and shoot again) at 4K, store those masters on cheap hard drives, and then edit & render them for whatever quality of HDTV you have now. Eventually, when you embrace 4K (which is probably the day that Apple officially endorses it in an Apple product), all those master files can be re-rendered to max out that OLED "cinematic quality".
Don't do that and you can't travel back in time and re-shoot any of that footage at 4K. How much I wish I could go back to the 1970's-1990's and reshoot precious home videos at 4K now! Instead, I have to settle for VHS and 8mm quality scaled up on 1080p HDTV screens. Many of those dear relatives shot at those low resolutions are long-since gone. Many of those events can't possibly be restaged. Children can't be children again. I'd get it while I can.
Why do they have to charge "too much"? The guts of an

TV are the same guts as a stripped-down iPad. If an iPad can have the A8 and an A8 can play back 4K, it could be the next guts of a new

TV that can play 4K. Personally, I wouldn't mind one bit paying several times $69-$99 for a 4K-capable

TV4 with some of the other rumored benefits. But I don't see a reason a 4K

TV would automatically have to be priced a lot higher than the current

TV when the guts that make it go would be just an A8 instead of an A5. Was iPad pricing jacked up to "too much" because the A8 cost so much more than the A7? A7 vs. A6? A6 vs. A5?