What do I care how many Raspberry Pis I can fit in the same space as a used Thinkpad which brings a display, keyboard, battery backup, and myriad high-speed IO ports beyond just USB, when we're talking about a stationary server role?
I'm going to go out on a limb and assume the average HNer already has numerous retired laptops collecting dust in a corner, all more powerful and better suited to connecting high-speed storage to than any Raspberry Pi. They're already wasting space and have already been manufactured, instead of adding more e-waste piecing together Pi-based storage contraptions just turn one on and set it up for server duty already.