This idea of things exist for a reason is grounded in the assumption that everything in nature has a purpose, which is no longer the god-given truth (the irony is intended) after Darwin. In fact, the talk of purpose is usually an argument to deny all other possibilities of change and keep the status-quo, though today's bureaucratic, government funded institutions have almost nothing in common with the Newman's ideals. Instead, the talk of purpose after Darwin is no longer an innocent appeal to natural tendencies, but an intentional rhetorical expression of power - and it should be recognised as such.
Indeed, an institution may not have any inherent, god-given purpose does not automatically lead to the conclusion that it should not have one. In fact, if we accept that the university does not have some kind of timeless purpose and identity, but rather a socially evolved institution that survived when the popularity of Church dwindled and Kingdoms fallen, it allows us to see what gives the university a role in the making of modern societies. But the post-modern abandonment of a search for purpose and instead living with the preoccupation of day-to-day business, the reality in many universities, may be a sure route to the vacuous rhetoric of 'quality' (as Bill Readings point out) and to eventual obsolesce that follows, with the university label is slapped on to an increasingly variable institutional forms, making, in turn, any talk of purpose completely unsuitable. In this context, whether the 'University' will survive the 21st century remains an entirely valid question.