Self-help folk notoriously don't give evidence for efficacy of their procedures

Anecdotal evidence is still evidence.

Note that one of EY's rationality principles is that if you apply arguments selectively, then the smarter you get, the stupider you become.

So, the reason I am referring to this cross-pollination of epistemic standards to an instrumental field as being "dumbass loser" thinking, is because as Richard Bach once put it, "if you argue for your limitations, then sure enough, you get to keep them."

If you require that the "useful" first be "true", then you will never be the one who actually changes anything. At best, you can only be the person who does an experiment to find the "true" in the already-useful... which will already have been adopted by those who were looking for "useful" first.