The principle applies elsewhere, too. He's right - tailor your resume.
Also, make sure what you rock at is big and clear and up-front and featured. Because you hope your resume is being read by somebody who doesn't just read resumes all day.
Then put keyword soup at the bottom for recruiters, if you need to.
I've been reading Land the Tech Job You Love [1] recently, and he says the same thing about putting "keyword soup" at the bottom. But he also recommends naming the section something like "Buzzwords" so that human readers know to skip that section. "Oh, this is obviously to satisfy the automated resume screeners." I'm not so keen on the idea, but probably because I usually apply to companies that are too small to use the automated resume screeners.
It's not for the human readers to skip the section so much as to simply acknowledge that you're doing it for the machines.
If I'm a human and I'm reading a skills section that includes PostgreSQL, PL/pgSQL, SQL and RDBMS, I might think "Aw, she's padding her resume, those are all related." But if I slap a "Buzzwords" section on there, now it's clear why it's there.
And I do think that's important. Say you've got an HR drone who is told to look for candidates who know SQL. He might see a resume including Oracle, Postgres and DB/2. We all know those require knowing SQL, but the HR guy doesn't. He won't see the magic word "SQL", so there's a good chance your resume will get ignored.
That example is also why I suggest that no hiring manager ever let HR screen resumes. It's just too important to be left to a filter that doesn't have the proper knowledge set. Sure, your recruiters at Google and Microsoft and other big operations know these tech things. But most tech jobs aren't at tech companies like that.
You can improve signal-to-noise by listing in categories ("best", "okay", "seen it before", "academic-only") and then humans can get something out of it too. Or you can call it a loss and treat it like what it is.
The idea of listing categories is fine, but don't rely on those descriptions to give enough detail. What you think might be "good" knowledge of X might be strictly amateur to someone else. Better to tell stories and give descriptions of how you've used the technology in question.
Also, if you know something good enough to say that you're good at it, there better be multiple bullets up above explaining how you've used that technology. I've had resumes where someone says they have expert knowledge in a given technology, but nowhere in their work history do they have anything that says that they've used it. You know Oracle? Then you have to have it in a bullet up above.
Another way that you can get those details in the resume about what you know is by quantifying as much as possible. Instead of saying you wrote a Ruby app to do such-and-such, say that you wrote an N,000-line Ruby app to do such-and-such. The numbers give a sense of scale that's missing without it.
Also, make sure what you rock at is big and clear and up-front and featured. Because you hope your resume is being read by somebody who doesn't just read resumes all day.
Then put keyword soup at the bottom for recruiters, if you need to.