That's not true. A static site served by Nginx (or a non-static one but with proper cache implementation) can do miracles even on a relatively cheap VPS.
Heck, my wordpress site (with cache plugin) survived the front page served over my home cable modem (5Mbps upstream)! And that is old-school Apache prefork…
You are totally right, but this is a low-traffic blog, i wasn't expecting anything above 2k daily visitors and supercache, for some strange reason, acted funny before not updating the pages correctly.