“However, if the people from lower tier schools don’t get the interview slots, that’s still a huge advantage to attending an elite school.”
It’s an advantage. Like I said before, however, life doesn’t end at undergrad. MBB hire PhDs. Both MC and banks hire from MBA programs (and master’s programs*). Big Law hires from the T14. MC takes industry veterans who actually know something (IB does too). You have to be stellar enough to get in to a PhD or T14 or M7 or be a heavy hitter in a field but you’d have to be stellar at some point anyway.
In any case, MC and (especially) IB and (very especially) Big Law aren’t the end-all and be-all.
*One guy I met went to Columbia’s Teacher’s College just to land something on the Street. He ended up in S&T at GS.