Note that one often-cited counterargument to its seeming "absurdity" is that it evens the playing field in a fairer, more meritocratic way.
No matter your background, what school you went to, or what randomized experience you got in previous jobs, every person has equal opportunity to study and practice the same algorithms on their own (as opposed to being lucky enough to be able to afford a top-tier $$$ CS education, or to being lucky enough to have the connections or chance to get certain previous jobs).
And thus, when applying to jobs, it becomes something more akin to a raw-ability IQ test, which you can argue is "fairer", especially when management realistically knows developers might be shuffled around all the time, and that the extensive SQL experience they were hired for will mean nothing when project requirements switch to a basic key-value store.
On the other hand, if you are interviewing for a highly specialized position that is fairly certain not to undergo change, then it makes sense that specialized experience could rightly count for far more than any kind of generalized intelligence or ability.
> every person has equal opportunity to study and practice the same algorithms on their own
Well, that's just not the cause - there are many groups of people who lack the opportunity to study and practice. Couple of examples: people with kids, people working 12 hour shifts, people without access to teaching materials, people without a sufficiently advanced machine to run dev environments, etc.
It's "fairer" if you're a recent college grad, probably single, definitely no kids or other family obligations, fresh out of school, and without much to lose if you spend all your free time studying for a "fair, meritocratic" test.
No matter your background, what school you went to, or what randomized experience you got in previous jobs, every person has equal opportunity to study and practice the same algorithms on their own (as opposed to being lucky enough to be able to afford a top-tier $$$ CS education, or to being lucky enough to have the connections or chance to get certain previous jobs).
And thus, when applying to jobs, it becomes something more akin to a raw-ability IQ test, which you can argue is "fairer", especially when management realistically knows developers might be shuffled around all the time, and that the extensive SQL experience they were hired for will mean nothing when project requirements switch to a basic key-value store.
On the other hand, if you are interviewing for a highly specialized position that is fairly certain not to undergo change, then it makes sense that specialized experience could rightly count for far more than any kind of generalized intelligence or ability.