If we don't have monitors that can view it natively and our computers can't even play it smoothly when we download it then what the heck is the point of 4k?? Useless. I have a top of the line rMPB 15'' and I'll let you know if it can play it.
As a video professional 4K is more future proof, first of all. I'm not sure if you are making this about 4K in general or about the Note 4 and other 4K capable phones. There was a day when what you said applied to 1080p as well. As retina screens become the norm, 4K is becoming more normal as well. 4K to me already seems outdated honestly as 5K and 6K have been around for some time. If I was buying, say, a Panasonic HC-X1000, I would be content with its 4K capability and not feel like it was outdated. But for the ultra high end market I think investing in 5K and higher is a better idea.
Back to the discussion about "useless", the idea is that since many people have 1440p 27" displays, 4K will be sharper on it than 1080p even if you only select the 1440p option on YouTube and not full 4K. That is why I said it looked better than my Canon, because one played 1440p downscaled, the other upscaled. I don't know of any cameras that shoot quad HD as the top setting... usually it is 1080p or 4K and higher. For that reason, 4K is certainly not useless.
