What are you suggesting as an alternative? There aren't exactly any new Classical works being written. It's the same as any literary study. If you study the Victorian English novel, you'll be looking at the same old material that everyone else is. Charles Dickens isn't going to rise from the grave to write an Oliver Twist sequel. We don't have the Greek and Roman texts that we do today because we found them in a sealed ancient library, but because generations of scholars have deemed them worthy of reproduction. They have been copied and copied over the years to reach us now. It's only rarely that we discover new texts, and these are often additional fragments of known works or older versions of extant ones.