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…
People just expect 10 Heroku dynos to handle the load when that's not even close to necessary haha.
My nginx with uncached wordpress on digital ocean held up as well.
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.
I've had a static site hosted on the cheapest shared hosting plan I could find take a stint on the HN frontpage without any problems.
Not really. I've got a bog-standard Wordpress site and it coped just fine. I use Cloudflare to save on bandwidth costs though.