Feedback on Prospective Students' Writing Samples

I was recently struck by the thought: professors carefully read and assess the writing samples of (at least) those prospective graduate students to whom their department offers admission. So why do they not write up their assessments (including constructive suggestions for how to improve the paper), and offer this to the prospective student along with the offer of admission? What better way to signal your commitment to helping the student develop as a philosopher than to provide such help before they even arrive?

It seems individually rational for departments to start doing this, since it seems likely to give them an advantage in recruiting the top students, relative to departments that don't make such an effort. (At least, I imagine I would have been influenced in my grad school choice by receiving useful, detailed written feedback on my work -- it would make me look much more favourably upon the school in question. I assume other students would respond similarly.) Since professors care about attracting the best students, it seems likely to be well worth their while to write up such feedback, at least for the students they want most to recruit.

It also seems globally desirable that this become standard practice. Given plausible assumptions, it should help match up students with the professors/departments that are most likely to help them develop as philosophers. This is obviously good for the students, and what's good for grad students' development is good for the discipline. Further, it also seems good for the professors to be able to increase their chances of recruiting the students they want most among the admitted class (at the cost of reducing their chances of recruiting admitted students who are desired more strongly by competing institutions).

And, quite apart from the assortive benefits, it's just intrinsically desirable that all this reading and evaluation, on the part of some of the top minds in the field, not go to waste. I'm currently revising my old writing sample, since I rather like the paper, and I'm struck by the thought that I could have received helpful comments on it from experts at seven top schools. Moral philosophers at those institutions read the paper carefully enough to decide that they wanted me to spend the next five years studying with them, so presumably they also had various thoughts on how the paper might be improved. But this invaluable information was never communicated (at least in writing -- I can't remember my visits well enough to recall whether it came up much in discussion; I would have been too flustered to absorb it then anyhow). What a shame!

Has anyone had this idea before? Is there some reason why it isn't as desirable as it prima facie seems to me? (If not, here's hoping the idea starts to catch on!)