I think you're knocking down a strawman; many people don't think he's a retard so much as a mediocre author who writes a sometimes exasperatingly mediocre blog.
None of that means he can't be a brilliant programmer. I'll admit to being a little surprised that SO took off as it did, and I certainly don't think that being relentlessly hyped again and again by both blogs explains all of that success. But I'm not sure why that proves me wrong; am I supposed to start liking Atwood's blog now? I opened it to have another look; the top post starts with a pronouncement that "abstractions are powerful things" (oh God), and then goes on to tediously argue that they invariably leak, but are still powerful things. No thanks.