Or is it just a term made up to find an easier reason to reject job applicants?

So it looks like the consensus is “overqualified” is a euphemism for

• “I’m afraid you’ll leave this job because I’m assuming you’ll have better chances elsewhere” aka “you won’t accept being my slave forever due to lack of opportunities”
• “I’m afraid you might actually understand how shitty it is here and want to improve things. can’t have that”
• “I don’t want to figure out how much to pay you when you know your worth”
• “You cost too much”
• “I have other reasons, but won’t say them”