MIT alum here. I know what you mean; the pressure can be tough. But also, they've got a lot of resources on campus to help.
I'm going to be on campus tomorrow and Thursday if you're interested in meeting up and talking about the stress. My email address is in my profile.
Maybe a more useful rephrasing is that your presence at the institution is a blessing, a gift, given whether you currently deserve it or not. Enjoy the gift and grow into it.
However, for some students attending Harvard, Stanford, Oxford or Cambridge can be an expectation and a realistic one at that if they have been given every opportunity to increase their chances of entry thanks to their parents influence and wealth. I understood the Author to be addressing these students. Perhaps they're a minority, but looking at the ranks of politicians and World leaders (from wealthy families I might add) coming from these institutions, it looks like more than just coincidence to me.
Saying "understand that you are here through very little of your own merit" is a recipe for causing already overly stressed students to do something rash, like jumping out of a building: http://web.mit.edu/~sdavies/www/mit-suicides/ (this list isn't even up to date).
Motivating people to work hard to feel like they've earned their place is a completely different thing than reinforcing the doubts and insecurities almost all of them have anyway.
The pressure at this place (and it's the same at any top-tier place) has been almost too much for me to handle sometimes, and that's without foolish words from foolish people designed to increase it.