I agree. People step up in size to a big 4k TV and HD and SD looks worse on them. Higher quality TVs with better upscaling fare much better.
Spot on. For a long time my 720P tv was a much better picture than 1080p and 4k TVs I had bought since. Which is why I always make sure I buy a TV with really good upscaling until the day comes when everything I watch is 4k.