You really, truly do not get what me and others are saying about DPI, do you?
If you make that giant TV the same DPI as the computer monitor it's not going to make you want to sit further away, you will want to sit the same distance away as from the desktop monitor to retain the same sharpaness. For that matter we
don't want a 47 inch monitor (if you can find one in that size for the consumer market that ISN'T a TV!), we'll want the 4K 20-some inch monitor instead to overcharge that DPI. Seriously,
take a look at this, at best you might have an argument for people who are in the middle, they want higher DPI yet also want to sit a bit further away, but you're not making that argument. If you want to keep that same 1080p sharpness you get from your monitor for your comfy couch gaming you... just get a big 1080p TV. Sit the correct distance away, and it is effectively the same as far as you can discern.