I had a conversation with someone today who said, and I've heard it before, "managers shouldn't be in managerial positions unless they can roll up...

I had a conversation with someone today who said, and I've heard it before, "managers shouldn't be in managerial positions unless they can roll up their sleeves and do my job". The employee is an Accounts Receivable Specialist at a firm (and a previous student of mine). His manager is a CFO. I know a lot of people echo these thoughts, but what is wrong with the rationale behind this statement/position? What do you think?100 words or more no format needed

I had a conversation with someone today who said, and I've heard it before, "managers shouldn't bein managerial positions unless they can roll up their sleeves and do my job". The...