This is a worthless argument. It basicly implies that we should NEVER increase the pixel density of TV screens for home use since 50-60" will probably remain as

This is a worthless argument. It basicly implies that we should NEVER increase the pixel density of TV screens for home use since 50-60" will probably remain as the mainstream market size. Yes there will be a difference. We have all these anti aliasing technologies because we want everything to look as smooth as possible. In the same logic, however fine images look in FHD, it can always be finer. Perception of moving images are not my field of study, but I could pose a very logical reason why higher resolutions are required. Consider a simple frame within a chronological video, at any given resolution. From one frame to another, there will be a refresh rate limit because you cant not change your image by half a pixel. At a higher resolution this refresh rate limit will be raised proportionally to the resolution increase.