Definitely agree with you there, but I also remember very clearly when people were saying similar things about 1080p. Things like why bother, shoot in 720p, nobody can tell the difference etc.
Of course, you can see the difference, but its how far you are sitting to see this difference. Not to mention screen size. Apple's retina display, the ratio - screen resolution : screen size is variable to suit minimum viewing distance.
I agree 100%, I was just quoting things I heard when video on the web started becoming just a little popular, which is why I said "when people were saying", as they are the things I heard.
I have always shot video in 1080p as it is always better to future proof whatever you are making. When I have a camera than can shoot 4K I will do the same, as it is better to downsize that to 1080p if necessary or just keep at 4k if the file sizes etc permit.
I think the advancement of technology is great, and while 4K will be around for a long time, I think it will not remain the top res for as long as 1080p has, which is why I would not be surprised to hear about cameras which shoot at even higher than 4k in the not so distant future.
If Windows 9 is going to support 8K resolution then my thinking is that some companies will just jump to that. I, and many others will not buy a 4K TV as my relatively new 1080p TV is fine for now. 4 or 5 years then I may change.
Like I said I am not good at the physics and maths behind all this, I just have a feeling that 4K will not be the "top" res for as long as some think it may be.