Let me be the judge then. For a site serving 13 million pageviews per month (80% of them are uncachable searches) we use 2 servers with about the same configuration (same memory, cpus). The database server has an average load of 1 and the application server (that is serving a bunch of other sites as well) is under 2 most of the day.
We have 1/2 of their capacity running an equally heavy site (all sites running on those servers make up 16-18 million pageviews per month). So if they run on 1/10 of similar sites, we run on 1/2 of their 1/10. Even better we pay 100% percent less of what they are paying. I wonder how smart Atwood is.
I don't intend to be a smart ass here. I would never say "Hey we run with 1/10 of your capacity, you are stupid" because performance heavily depends on the application. StackOverflow probably has a 90% cache hit ratio (86% of visitors are from google that land on some question asked some days or months ago). So 3 servers for a cache and forget site (logins and bits for pages that change often can be cached too) serving 16M pageviews per month is below average. They maybe doing a whole lot of other things in the backend that we don't know of , but the same goes for the other sites that "their programmers are stupid and use 10x hardware."
I would expect them to say what problems they solved and how instead of bragging about how awesome programmers they (he?) are.