Demanding a publication record in order to write a recommendation letter makeshas no sensepoint at all to me.
Let us give an extreme example: suppose someone publishes in CellCell by his/her third year in graduate school, and publishes again in NatureNature when he/she finishes the graduate program. This guy will not need a recommendation letter at all.
On the other hand, imagine a hard-working fellow who is knowledgeableacknowledgeable, knows the field in depth and is good at designing experiments, but got unlucky because the biology of his/her hypothesis was not what he/she, norneither the supervisor, were expecting and, because of that, did not publish in a high grade journal or did not publish atin a fast pace. This fellow is the guy who needs someone to state his/her qualities and to be vouched for. The recommendation letter is redundant for people with high grade publications.
So, writing recommendations onlywhereas it is usually essential for people with a good publication record is the same as pouring water into the seawithout them.