In general, I would agree, but wouldn't you be using the slow public key crypto only once to encrypt a symmetric key you've previously generated to destroy the

In general, I would agree, but wouldn't you be using the slow public key crypto only once to encrypt a symmetric key you've previously generated to destroy the files? I would assume that symmetric encryption still is more than fast enough to be scary, especially with current CPUs and native AES support. I would think this is more laziness/incompetence of the developer than an optimisation (even more so as in the OP's article, the file were properly(-ish - I would have used AES over RC4) encrypted, but the symmetric key was attached to the file).