This is opinion versus opinion. I'm sorry to say there's no real content here. The author went from Yahoo to Craigslist so there's no such thing as premature optimization at that scale and with the small staff at CL you can be sure that chasing NoSQL as a fad can ruin the company. Obviously he doesn't fit the bill of the essay he's criticizing but most devs don't experience the scale of his problems.
You can't do the topic of NoSQL vs SQL justice with an essay because it would just be semantic, we're talking about a different theoretical representation of data structure. You might as well scream "better taste!", "Less filling!".
Mine is based on years of experience, but I got the impression that the original article was written based on some cherry-picked reports of what a few companies said (as opposed to actually being there and doing it).
You can't do the topic of NoSQL vs SQL justice with an essay because it would just be semantic, we're talking about a different theoretical representation of data structure. You might as well scream "better taste!", "Less filling!".