Well-
An education degree is a little bit more than just a little certificate that says you can teach in such and such state. As far as I understand, degrees in education focus on things like education theory, teaching strategies, child or adolescent psychology and things along that line. Just because a person has a masters in a particular subject doesn't mean they're qualified to instruct elementary or secondary education, because it's a bit more than just spewing out information for students to copy into their notebooks, (this is why I hate large classes, lecture halls, shit like that- it's not a good way of teaching.) Also if I'm not mistaken, most education degrees have a point of focus. Music education, physical education, social sciences education, etc. So, it's not like people are teaching blindly in a subject.
Teachers have their base salary and positions judged by their education as well. Typically, (at least in my school district,) teachers who went back and took masters classes in their field received a pay raise when they earned their degree. Why? Because they have even more qualifications, and it's something that isn't ignored when a school board is making a decision to hire new teachers. It's really difficult to place a teacher in a position when you consider the most crucial learning stages of a child. Would you put a very well qualfied teacher in a kindergarten or first grade class because age 5-7 is one of the more crucial stages of learning (spatial reasoning, creative thinking etc.) or based on the idea of a set cirriculum mandated by school boards, could you just stick anyone with an associates in elementary education in a kindergarten class and expect the same results?
It's bs to some extent, and I think it reflects on our current generation when most students can barely spell and can barely speak properly. However, due to limited funding by state legislatures and even less by the federal government, teachers educate their students with out of date textbooks, (My high school bought text books every 7 years,) and teachers become apathetic because they feel they're overworked.
Back on topic, the mastery of a particular subject doesn't make you more qualified to teach if you don't possess the ability to communicate the information to your audience, (children.)
Oh. Teaching in Canada-
http://www.ctf-fce.ca/en/teaching/teaching.htm#r
I tried looking for some european information, but I couldn't find anything, heh.