I don't agree that Affleck and Damon are "Two of the worst actors to have ever lived" but I do agree that this an incredibly unoriginal, intellectually lazy and just plain bad idea.
I am not a huge fan of Westerns and must admit I have not seen Butch Cassidy & The Sundance Kid. I do however, know that the movie is universally regarded as a classic and its impact on pop culture has been immense, so much so that even someone like me knows a bit about the film and its importance.
I will most definitely not pay money to see this movie and will only suffer through it if I am forced to.
As for whether Hollywood will ever learn when it comes to making all these remakes. The answer is a very big NO! This answer will remain the same as long as movies like this have an audience and continue to generate a lot of money for Hollywood 'Pezzonovante.' If the public refuses to support amateurish efforts at entertainment and chooses to solely see movies such as Bowling For Columbine, Donnie Brasco, Fahrenheit 9/11, The Interpreter, Mystic River, Road To Perdition, Sin City, Snatch, Syriana and Traffic things might change. But, until then, it looks like we are gonna see movies like "Godfather 2006," "Goodfellas Reloaded," and some sort of prequel to The Untouchables..Oh wait a minute, they're actually gonna do that last one...
