And once you start changing things, where do you stop? Are you going to start changing viewscreens, adding set extensions, add more people to backgrounds? Get rid of the skants? Redo the color timing to the current visual flavor of the decade (see the recent revision of The French Connection)?
The film is what it is. Fix it where necessary (missing shots, whatever), but if you want something else, make a new show.
Yeah I don't think they need to correct every mistake that was ever made, but we are talking about a very different format here. If bringing the show to HD makes some things stand out and look a lot worse
than they did before, then you're no longer presenting the show the way it was meant to be presented.
A lot of those effects were intended to be seen on old analog TV sets only, and CBS is simply trying to make sure they work on today's TVs, to extend the life of the show as much as possible.
So far, most of what they're doing is incredibly
subtle, which only the most nitpicky of fans is ever going to notice. So I'd say they're going about it just right.