What that message from Kagan means depends a lot on the attitudes of the person reading it.
We were told the same thing when we matriculated into medical school. I bet they say the same to every entering law, dental, and business student, too. Which are all examples of this "maybe bad or lazy" message being paired with serious educating. And that doesn't have to be a paradox. It can just be a distinction that an important step is over. Or a signal that "typically everyone who gets this far is serious and you're one of them, so you're set." Either way, we can assure ourselves that even though I received this message from Dean Paz at a first year "white coat ceremony" and was told "P = MD," as in "pass and you're a doctor," which was all true and that almost everyone graduated, getting an M.D. still took some doing. That the message doesn't (have to) contradict real education.