One thing to keep in mind is that many reform critics, including myself, have worked with Gates and other big foundations in the past, and one way or another been burned by the experience. In my case, Gates gave my colleagues and I a lot of money to create a small neighborhood high school in Providence, and then after Gates decided they weren't interested in small schools, we were hung out to try and closed, even as our test scores shot up and we had the highest college enrollment and retention of any neighborhood high school in the city.
Now, you can't blame Gates directly for our school being closed, but I think it is emblematic of their particular problem. That is, how can a massive private foundation -- but still small in budget compared to overall government spending -- improve education across the country in a measurable way in a short time frame? I think the short answer is turning out to be that it is impossible or extremely difficult, but in the meantime, they're going to thrash around from one increasingly disruptive option to the next, in increasing frustration, leaving a trail of orphaned initiatives in their wake.
In this respect, Gates is different than a lot of the more ideological foundations. Gates has a definite point of view, but they aren't like Broad or Walton or many of the others, which essentially have always wanted to disassemble public education. Gates has just drifted that way over time out of frustration, and it is hard to see what will stop that process.