Rocky is one of my favorite movies of all time, but I have to agree with Pirate that it does come across as being dated. The music, though inspiring, has a seventies, not a timeless, feel. Boxing is about 1/10 as popular as it was then. The sequels did not tarnish the original, anymore than Godfather 3 tarnished 1 (or 2, for that matter). The Wiz did not tarnish The Wizard of Oz, the Gone with the Wind sequel did not hurt the original. Caddyshack, Grease, Jurassic Park, Ghostbusters, Jaws, and many others had what most consider awful sequels made, yet the originals are still extremely popular.
Why in the world would remakes of Escape and Computer automatically be a problem? If they try to be faithful to the original, fine, that's a problem. But The Parent Trap had a very different feel than the original, and is a good family movie. The ideas from those bad movies could easily be used to make good movies now. I seem to recall a few scorcery and withcraft movies from the last six months that have done well, so Escape, in the right hands, can be far superior to the original, just as The Parent Trap is (IMHO).
If the Disney brand survived the Apple Dumpling Gang, it can survive Cinderella 2.
I'm not saying I'm completely supporting the way they are implementing the sequel strategy. I think they are overdoing it, and judging from the difference between Pan 2 and Cinderella 2, they are not producing these with consistent quality. But, again, as a supplement to original features, the sequels have a place in a succesful overall philosophy and strategy.