Why is 4K upscaling so bad?

Episode 1643 (2:00:00)

Greg from Apple Valley, CA
Sony Bravia Smart TV X950G

Greg was looking to upgrade to a new 4K TV, and got a Sony Bravia, and found the upscaling was terrible when watching live TV. A year later, the TV has gone out and he has to replace it. Will he have an issue with another 4K TV? Or should he just try and get and older 1080p TV. Rich is not a fan of upscaling, and the native resolution will always be better because upscaling can't invent resolution that's got clarity. Just watch it the way it is, unless it's a 4K native signal. Netflix and Amazon Prime, for instance, stream in 4K. But TV channels vary from 720-1080i-1080p.