Look if they are qualified to teach, then they are qualified to teach. That's all there is to it.
To get in to a teaching position requires dedication and extra study, things like Ph.D's or whatever. It is very competitive. Lots of people want to walk around with a title and be able to tell people that they teach university students. It sounds very intellect and high class for some people.
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If you are worried about future employment in an extremely competitive field or with an extremely competitive employer, then worry about the school, such as Oxford.
When you graduate you will have a qualification recognized all over the world. It's not like studying in India, where your qualifications are often not recognised internationally due to low quality control.
But yeah, if you want to get an internship at the UN, you're gonna want dux of Cambridge or something with a whole bunch of extra curricular activities on top of it.