Ask HN: I've been a programmer for 6 years, and I can't solve basic CS problems 8 years ago
Bingo. The reality is many people have no idea how to interview, so they fall back on the only thing they know: test taking in school, and studying for the test.
You don't want to just ask them to tick boxes, because first off some'll lie to you, and second, the dunning-kruger cases will lie to themselves. Can they communicate? Can they solve unseen problems? Can they do so comprehensively and rigorously? Do they know how to maintain a project for many years?
An interview method that can't tell the passionate hackers from the posers and pencil pushers is worthless.