"Sarcasm is stating the opposite of an intended meaning especially in order to sneeringly, slyly, jest or mock a person, situation or thing."
I don't think agreeing fits.
(See that? Agreement.)
In particular, when you "agree" with something that you have quoted out of context, it's quite easy to paint it with the opposite of its intended meaning. That's what the OP did -- he took a remark that wasn't intended to disparage the MBA degree, and turned it into something that did.
That's called sarcasm, whether wikipedia is your authoritative reference on the subject, or not.
It's always interesting when people declare what someone else is saying or thinking or trying to convey instead of just asking them to clarify :).
My main gripe is with anti-intellectualism and other forms of low-brow snottery in general, not so much with your specific comment.