For teaching subjects? I don't really have an issue with that, in theory. 5 years might be a bit much, but right now there are a lot of "subject teachers" who think that because they majored in something in college, they're qualified to teach it. Sometimes it works out great. We have an amazing first year economics teacher here who probably would run circles around other more experienced teachers. But sometimes people end up in way over their heads (witness recent threads about history teaching).
Thing is though, what will happen is that schools will hire teachers as English language teachers on paper, and then just have them teach whatever anyhow. Once they're at the schools and in the classrooms, who is going to actual monitor what the school gets them to teach?