"If you think about it, TV shows, particularly of the golden age era, were shot and composed to be perceived on a 20" screen across the room- lots of closeups and medium shots. Apparently lots of BBC and Thames stuff was shot on 16mm. I am working my way through the Buffy canon and lots of those shows are abysmally photographed- underexposed, highlights blown out, color off, etc. And things on low-res videotape wouldn't benefit one iota."
Those problems are most likely due to poor color correction during the transfer, not poor cinematography.
Classic TV shows like Twilight Zone were actually filmed in 35mm. If the original negatives are still available, they could be converted to 1920X1080 HDTV with as high picture quality as any modern film transfer. As pointed out here ad nauseum, the difference between good HDTV and DVD is striking - even on midrange equipment.