Because the studies are constructed by equally fallible humans, and almost always badly.
Cold shower attempted, but the plumbing was busted?
Such studies invariably wholly miss the point: when you have a language with powerful type support, error checking is the least valuable work you get out of them. Types do serious heavy lifting expressing semantics.
As a general rule for dev work, trying to make evidence based decisions is fairly difficult. There's just not that much evidence around yet that can make it obvious as to if in your particular situation what the best choice might be.
And at the end of the day you have to contend with being in a work environment where politics and personalities rule, not science (or engineering).
That said I do wish more devs would take an interest in the available quality literature. Unfortunately I'm far more likely at work to run into an Uncle Bob recommendation at work, than a recommendation of ACM's Digital Library.
And yet, per TFA, it’s not; at a minimum it’s clearly not “self evident”.
Why do we developers value our personal experience above studies, while dunking on average citizens for doing the same?
Guess we’re just as human as the rest of humanity; subject to the same urge to trust our own beliefs over contrary evidence.