[thwayunion]

Common Core is just a set of standards. This is a bit like criticizing the API because one specific implementation of the API is garbage; you may be right, or wrong, but what you're criticizing is not relevant to the API design, at least at the first order.

Some publisher's course materials may fit your criticism. Lots of expensive garbage in K12.

The material I reviewed was quite the opposite. Instead of memorizing one way of performing an operation, you learn many different ones, discuss why one might be better than the other in certain contexts, and even think through why two different algorithms implement the same operation. The students I worked with/observed emerged from high school with a level of mathematical maturity that most students don't achieve until well after their university Calculus sequence, if ever.

Two other thoughts:

1. Everything you just described also describes how most schools implemented mathematics education prior to common core. If this is how someone taught with common core, it's almost 100% certain that this is also how they taught before common core, and that this is how they would teach mathematics regardless of what standards they were following. What you are describing is a bad mathematics educator, which is a serious problem in the USA but is orthogonal to choice of standards.

2. Most importantly, I never got even an articulation at this level of detail. People were angry because pundits told them to be angry. There were no articulated reasons. Just, "CC = bad".