How do we distinguish between: "VCs are are selected because they go to school X", "school X is good at creating VCs", and "school X receives more potential VCs"?
My guess is probably more statements 2 and 3 for the usual suspects eg Stanford
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.
My guess is probably more statements 2 and 3 for the usual suspects eg Stanford