There are many many many many MANY reasons that top down reformatorium programs are a bad idea. But lets just focus on one for a moment.
Years ago our school had to implement a new graduation project program. Our principal met this challenge by putting a bunch of staff in a room to thrash out the details of how the new program would work. We met and we talked and we talked and we met, and eventually hammered out a whole program for the graduation project.
But we ended up with more than a workable program. We also ended up with a room full of people who understood how the program was supposed to work.
Management training 101 says that you want to give people the illusion of involvement in the creation of a program so that you will also get buy-in. But when you create new programs or reforms from the bottom up, your program creation is also your program training, and that is worth its weight in gold.
Apologists for CCSS keep blaming the various issues on a bad rollout. If only the implementation hadn't been flawed, they say. we would be gamboling through fields of common core daisies. But implementing CCSS from the top down absolutely guaranteed that the rollout would be flawed. The messed-up implementation is not a bug; it's an unavoidable feature.
Top down implementation means that none of the people who actually have to implement the program have any idea of what the program is or how it's supposed to work. Everything has to be explained to everybody, and that's a long process, a process not unlike a long game of telephone.
CCSS has been even worse than the average top-down implementation because it is so jam-packed with its own jargon. Teachers are sitting through training where hours are being devoted simply to getting everyone in the room to use the proscribed definition of "rigor." Teachers are spending days in seminars about "unpacking" the standards themselves, which is a nice-sounding way of saying "trying to figure out what the hell all this gobbledygook is supposed to mean to an actual classroom teacher.":
With bottom-up reform, everyone has been in the room working on a shared language of shared expectations together. That understanding emerges organically while the details are hammered out. But top-down reform has to be passed down in its entirety, all the way down to the actual words being used. The program becomes like bad stereo directions that are passed down as a xerox of a xerox of a xerox ad infinitum, each one presented by someone who has his own maybe-faulty understanding of what he sees on the bad copy that's been handed to him.
If the most genius edu-whizes in the world came up with the best school reform system ever and tried to implement it this way, there would be tremendous problems. Start with a hackneyed mess of garbled muck like CCSS, and you are absolutely guaranteed a flawed implementation.