[HighlandSpring]

It could be mostly 1)

If you hire a smart kid with an MBA from stanford and he gives you a bad name with a series of mistakes, well, bad apples happen. If you hire a smart kid from a no name university and the same happens people will be quicker to blame you.

Credentialism is a thing for the same reason brand recognition is a thing. When a product with good reputation fails it's bad luck. When a product with bad reputation fails it's to be expected. Power perpetuates.