Well that's completely nuts, and so out of touch with reality

Indeed. That was exactly my reaction. In fact, I completely fail to see the connection between "slow I/O loop" (whatever that means) and "low-level language". If one implies the other, then because I can write a tight I/O loop in ASM, does that mean assembler is not a low-level language?

I always believed high- and low-level refer to the ease of expressing complex ideas in a programming language, not to I/O speed -- or any other kind of speed, for that matter. On that score, Perl is squarely in the high-level language camp.