HTDV is great! I enjoy watching my 50-in 1920x1080 TV from about 8 feet away when playing blu-ray discs of great movies or great shows. Sometimes I'll get a HD stream from Netflix that also looks great on the TV. The crisp detail is wonderful! Head shots showing each individual misplaced hair or each stubble on a 5-o'clock shadow.
However, sometimes the crisp detail blown up on such a large screen isn't so great.
I have seen old films on HD (Blu-ray or a Netflix HD stream) where the higher definition accomplished nothing more than to make the film grain more visible, painfully visible, like dancing sand for light-colored walls. I am sure the Producer's objective wasn't to show off the film grain!
Some of the magic of older shows is ruined by 50-in screens by making quite visible the threads for holding models (how Supercar flew) or tugging on some objects to move them. Back when the typical screen was B&W and only 8 to 12 inches, or in color with the screen size of 14 to 21 inches, one didn't notice those strings, but the bigger the screen, the more magnifying of the otherwise-unnoticed strings takes place.
Some films have lots of flaking (bright spots from where the emulsion had flaked off the film) or scratches, and the poor quality of the film gets accurately captured to DVD or stream, and those flaws are "in your face" on a big HDTV.
There are also other artifacts from filming off of TV screens (how some of the 1940s and early 1950s TV shows were preserved) or ghosts introduced by videotape that get copied onto the DVD or stream.
So, do you just grin and bear those magnified imperfections? Or do you have ways of dealing with such imperfections? Do you keep an old or small TV around for just such occasions? Or do you have some magic box that will shrink the image or clean up the image? Or some secret TV setting? Or do you avoid older content unless it has been painstakingly restored to its original grandeur?