CGI CAN ruin movies. You've got folks like Michael Bay, Stephen Summers and George Lucas who are like children who just discovered masturbation and can't control themselves, throwing CGI into movies just because they can.
Then you've got geniuses like Sam Rami, Stephen Speilberg, and Ridley Scott who understand that CGI has it's place. They understand that CGI is meant to ENHANCE a movie, never BE the movie.
Yes, if all the Michael Bays took over Hollywood, I agree, they would ruin movies with too much CGI, but if we can keep ourselves under control I believe it has its place.