And there is the trick... those are still images, but you wouldn't notice those effects in a moving picture any more than you noticed these effects when you saw the movie.
Audiences today like this.
TOS is from a different era... an era where early TVs and bad reception provided the poor image quality. All that is removed when we watch TOS today, and it has most likely hurt it's perception by non-fans.
Fans, on the other hand, are constantly looking for every little detail and so like the ultra clear images. Therefore
reremastering episodes in this way would be an attempt to get a wider audience (outside the fans).
I honestly think this would work. And it can be done at very little cost.