Over in blue lab coats, a comment was made about the downside of only accepting students that looked promising for tenure track positions. Namely, this criteria would bias against students who are unlikely to be accepted into tenure track positions.
Now, this bias can take one of two forms. There can be irrational discrimination (such as age or gender-based). I think that we can all agree that this type of discrimination is a bad thing and should be avoided.
But at a more pragmatic level, the scheme where one student in ten succeeds (and these appear to be optimistic odds) at the primary career path of a 5+ year high intensity training program seems to need revision as well. If the goal of the academy is to produce the next generation of academic researchers then we need to fess up to the unfair nature of over-production.
And don't get me started on the whole "non-tenure track" movement in medical research. Vile!