Advice: on protecting grad students from their own optimism

I've written about how lucky I was to get the academic position I currently hold, and how I was prepared to quit science if I hadn't gotten it. I've suggested that current grad students hoping to go on in academia follow my example: recognize that the odds of success are long, and have a backup plan.

A fine and sobering essay over at Inside Higher Education reinforces this message, while also suggesting that it may fall largely on deaf ears. Grad students are atypical: most were at or near the top of their class in school and college, and so they've learned to be optimistic about their academic abilities relative to the academic abilities of their peers. Even though that optimism is no longer justified.

As a mentor, I'm not sure what to do about this, beyond what I already do. I already talk frankly to prospective students about their long-term goals, and the likelihood of achieving those goals, before they even formally apply to join my lab. I'd be uncomfortable doing more than that--for instance, refusing to take on students whose long-term goal is a career in academia. That smacks of paternalism, as if I knew better than them what would make them happy. But then I read things like this IHE piece and I wonder if I'm doing enough.