A high GPA - that's an understandable requirement - but to base it arbitrarily on a 'top-tier' university is depriving qualified, talented employees from consideration.
Unless your are google or facebook, you are not going to be able to just turn away qualified people. It makes it too easy for your competition.
I, for example, went to a state school because quite frankly, I was not really interested in taking on hundreds of thousands in debt to finance a college education. I was accepted to a couple of top-tier universities but for financial reasons, attendance at such schools was not feasible.
Creativity/individuality/freedom/etc are all very highly valued and encouraged at the best schools. Harvard was remarkably open and innovative. MIT even more so.
(Tangential, in response to the article - Harvard's very accommodating and even encouraging of people taking time off school to pursue other things. They have an indefinite leave of absence policy, which means that if I ever decide, 2, 5, 10, or 20 years down the line that I'd really like to go back to school and get a degree, they'll let me come back. Very nice and farsighted people.)
That's great. I wonder if many (any?) other universities have such a policy? At my school, I would have to formally re-apply after being gone for a year or so. That's the sort of policy I would encourage my children to take into account when they're choosing where to go to school.