I agree with you, the problem at a large corporation like ours is that the process ostensibly "works" - the candidates we are hiring are good and it's hard to argue that by expanding more effort(and more money) on widening our pool of candidates would result in even better candidates than the ones we have. The argument you'd need to fight against is basically "we already have a 1000 candidates, if you can't find someone suitable within a thousand people then maybe it's not the candidate pool that's the problem". The pool could be better and include people who are just as good(or better) but don't have a university degree - but again, that's money that would need to be spent and it's very hard to make such an argument in a corporate setting where people who make these decisions aren't the ones participating in the process.