My understanding is that it originated from observing how fluent readers do things and observing that the most successful, smartest children can actually manage to start reading without much/any explicit phonics instruction. So you could naively look at who ends up reading the best and how did they do it and think that perhaps that makes sense to do for everybody. The problem is that the sorts of techniques that work for outliers are going to be very different from the sorts of techniques that work for the median.

It wouldn't terribly surprise me if we walk into a similar trap with math. Like when I took a look at some of the common core math, I saw strategies that I use for arithmetic, where like sometimes I might do four-digit multiplications starting from the most significant digit with a sequence of approximations/corrections to arrive at the correct answer. It wouldn't terribly surprise me if this sort of thing just doesn't work for the median person, but from the little I've looked at it, it seems like the effects of CC math are mostly neutral anyway.