Bill Gates 
World Economic Forum / FlickrCommon Core critics contend that national education standards will erode local decision-making on school issues while promoting a national curriculum of sorts. Most Core proponents generally dismiss these concerns as unfounded.
But Bill Gates, a major financial backer of the standards, was atypically direct about what peddlers of standardization are trying to accomplish during a Politico event on Monday. Rather than defend Common Core from accusations of creeping nationalization, he finally confirmed that yes, this is exactly what Core proponents are trying to accomplish—less local autonomy is a good thing, as he says in the video:

"Common Core I would have thought of as more of a technocratic issue. The basic idea of, 'should we share an electrical plug across the country?' Well, you can get partisan about that I suppose. Should Georgia have a different railroad width than everybody else? Should they teach multiplication in a different way? Oh that's brilliant [sarcasm], who came up with that idea? Common Core, the idea that what you should know at various grades, that that should be well-structured and you should really insist on kids knowing something so you can build on it, I did not really expect that to become a big political issue."
There you have it. Gates views the education system—the many myriad ways Americans could pass on knowledge to their children—as akin to choosing the correct railroad track size. The implication is obvious: after all, there is only one right railroad track size! Similarly, there is only one correct way to teach children, and all children must be taught that way, according to Gates.
This way of thinking goes against everything the reform movement has come to understand over the last few decades about what works in schools: greater standardization is not the answer; schools languish under stifling centralization; every kid is unique and has different educational needs; and local authorities—especially parents—are best suited to the task of plotting their children's educational paths. 
Nurturing the mind of a child is an infinitely more complex task than choosing an electrical plug. It's not as simple as plugging the right cord into a child's brain and flipping a switch.
Gates says that Georgia shouldn't teach multiplication a different way than the rest of the country. But what if there is a style or method that works in Georgia but not New York? What if Georgia discovers a better way? 
And even if it were true that all U.S. student should be learning the exact same thing in the exact same way, no reasonable person could be persuaded that Common Core is it. That's because scant evidence exists in Common Core's favor—backers are relying on little more than their faith in an unproven methodology.
Standardization isn't good, and these specific standards aren't good (or at least, there isn't a lot of evidence in their favor). Which side in this debate is being unreasonably ideological, again?