When you understand exactly how the people who have operational responsibilities think about their jobs, you begin to understand that things work in a certain way. MMT has done a very good job of translating that situation and those facts to a wide audience. Who doesn't like it? The people brought up on textbooks which give you an essentially fictionalized accounts that are rooted in the ways economics wrote and thought maybe a century or a century-and-a-half earlier, and have not changed very much since then, except becoming more complicated and more abstract and more remote from reality.