Requiring a PhD to teach serves the same purpose as requiring a degree to apply for a job: an arbitrary but easy to apply filter. While PhDs are research-orient

Requiring a PhD to teach serves the same purpose as requiring a degree to apply for a job: an arbitrary but easy to apply filter. While PhDs are research-oriented, in reality you can end up in a research or pedagogy track depending on (a) what you want and (b) how your research progresses.