There’s plenty to critique within Fareed Zakaria’s new prescription for fixing the failing American education system.

But his latest contribution to TIME shows he understands some of the problrms standing in the way of real reform.

Bill Gates has spent about $5 billion trying to research and reform American education. I asked him, if he were running a school district and could wave a magic wand, what he would do. His response: hire the best teachers. That’s what produces the best results for students, more than class size or money or curriculum. “So the basic research into great teaching, that’s now become our biggest investment,” he says. One study estimates that if black students had a top-quartile teacher rather than a bottom-quartile teacher four years in a row, that would be enough to close the black-white test-score gap.

There are many more ideas, many of them worthwhile and worth trying, but you can get lost in the details of the education debate. These two seem simple–work more and get better teachers. Yet implementing them is anything but simple. They bump up against an education system that is deeply resistant to change and teachers’ unions that jealously guard their prerogatives. All the specific measures that would allow students to work more and good teachers to be identified and rewarded–more days, longer hours, merit pay–are mostly opposed by the teachers’ unions and other guardians of the status quo.