> The famous fizzbuzz test simply asks "are you aware of the modulo operator?"
Nope. The famous fizzbuzz test simply asks "can you actually write code at all?", because it turns out that some people applying for software development jobs basically can't. Even people with relevant-looking experience on their CV/resume. Even people who talk convincingly about what they've done.
(If you don't know about your preferred language's modulo operator but can do truncating integer division, you can do FizzBuzz that way instead. If you don't know how to do division, you can do it by having counters that count up mod 3 and mod 5, or one counter that counts up mod 15, and you don't need "mod" in your vocabulary to do any of that.)
Now, whether a candidate can write code -- like whether they know their language's modulo operator -- is also just one bit of information, but it's a really important bit of information that turns out to be tricky to get. This is also one reason for the "code on a whiteboard" tasks that many interviews use, which the author also doesn't like.
It may be that those are bad ways to get that one bit of information. But the author doesn't seem to appreciate what problem those things he criticizes are trying to solve.