At first blush, the new federal common core initiative sounds good. What could be wrong with having standards that are more rigorous and would be nationwide? Other than the loss of local control and the increase of funding tied to test scores, it should be great. When you forget about the requirements that aren't developmentally appropriate in the younger grades and the fact that the curriculum is being influenced by corporations that stand to profit off the roll out of new aligned curriculum, it's just great. And most states refer to them as state standards, which sends the appearance of local control, even though funding is tied to meeting the national requirements. A popular argument is that local boards do not lose control over which curriculum they purchase, but this freedom is limited because it must come from aligned common core materials. There are a lot of great sites with research reflecting the negatives of common core as well as narratives from teachers that have left the field with the introduction of these new standards, such as this Truth in American Education site and this article from a teacher who left her job.
This is not meant to be an all inclusive look at common core (that would take most of my time away from providing resources and links) but mainly a glimpse into my reasoning of why I am not including any references to common core aligned sites or materials. If you'd like access to a site with a researched list of each company and their stance, I suggest checking out the The Homeschool Resource Roadmap. Since companies change their position on common core, I will do my best to keep my site up to date and edit as needed. I removed a couple of posts where I formerly backed sites that are now explicitly aligned with common core or correlated with the standards and I will limit new recommendations to independent sites and companies.
On a final note, the reason that I refuse to support these sites/companies is because I don't want them to get the web traffic or any of my dollars That is still the best way to send a message and also support the companies that are standing firm against common core.