I've been a big advocate of things like PBKDF2 and such to slow things down where appropriate. But except for very specialized circumstances (and an RNG isn't one of them), we want cryptographic operations to be fast. In general, we want RNGs (and most things) to be fast and efficient.

And in particular, TW Cryptocards analysis never had to run the RNG. Just had to look at 2 million public keys already out there.