Pricing and charging for storage inside an organization is always ultimately a non-technical decision that has to balance who pays for it versus the consequences of it not being paid for. This is especially the case within organizations like universities, which have unusual funding and funding patterns (for instance, one time capex is usually much easier than guaranteed ongoing opex). We (the people providing the disk storage) know that there are ongoing costs to doing so, but the non-technical decision has been made to cover those costs in other ways than charging professors on a recurring basis.

(I'm the author of the linked-to entry.)