Earlier quoted context omitted.
We had curriculum standards well before Common Core. What specifically from Common Core enabled what you saw, in way which wasn't done before? > "we need to divorce the common core from the testing standards" The only reason Common Core exists is to have testing standards. Otherwise, without tests, a teacher is free to pick and choose. Which is what we had before this era of high stakes testing. Also, Common Core was…
I don't see anything in Common Core that would make a curriculum following the Common Core standards easier to teach than a curriculum that does not follow it. Here is the English Language Arts standard: http://www.corestandards.org/ELA-Literacy/ Here is the Mathematics standard: http://www.corestandards.org/Math/
The English Language Arts standard you pointed to, at p.35 of http://www.corestandards.org/wp-content/uploads/ELA_Standard... , emphasizes close reading.
Close reading is an example of something which is much cheaper to test at a mass scale. See http://curmudgucation.blogspot.com/2014/01/close-reading-20.... for a longer description of what that means.
My short version is that close reading, as meant by the Common Core Standard means that a student is given a short piece of difficult text and asked questions about it, without giving any context about what it means.
This is certainly easy to test. But mostly worthless as a skill since most works are much longer and contain much more context. As that Curmuducation link points out, "Twilight may be a work of light fluff, but a close reading of it unpacks how many truly indefensible and odious subtexts are lurking in its gooey pages".
That sort of close reading is much more important in teaching how to really read, but it's not easy to test, so not emphasized in Common Core.
You pointed me to the Common Core definition. However, a close reading ;) of Common Core is not enough to tell you how it's meant to be used or interpreted. That's why you have to look at, say, how people are being trained to teach in a Common Core system, like http://k12newsnetwork.com/blog/2014/01/14/a-closer-look-at-c... .
Quoting from the Curmuducation link: "Close Reading 2.0 is proof (piece of evidence #2,098,387) that CCSS was built to feed the testing beast."