Apple fans often justify the prices with this argument, but in reality, there is no reason to buy a machine directly comparable in all aspects, just the ones I care about. And that can be had for a fraction of the cost.

It's unlikely that this company needs all the hardware features of the Mac Pro - probably just the beefy GPUs. That's combined with the power density problems (and higher monthly costs) of this solution, compared to modern rack or blade servers, making it far worse value.

Compare this also to John Siracusa's woes over buying a new Mac: He wants a graphics card powerful enough to game on, and remain useful for a number of years. He wants to be able to get a retina display. He's for now stuck with a 2007 Mac Pro as Apple don't sell a suitable machine.