This is a fair point.
I buy that if an item of work is as a menial task that's well defined, like swinging a hammer or cooking a cheeseburger. What about for middle management positions who's job is not to swing a hammer, but to make sure that all hammers swung according to the executive's wishes?
Not being able to get rid of an employee that you no longer want around is not mutually beneficial either.
BTW, I think your use of "funsies" isn't constructive because it implies that somebody is firing people because it's amusing to them, rather than it being a business decision. I'd assume that firing people for "funsies" is exceedingly rare.