You can make an argument that the Mac Pro provides real value over competing systems. These $700 wheels look pretty, but you can't argue that they provide real value over $20 alternatives like this [1].
Sure they do, they provide a clear status symbol which people at every level above subsistence value more than "real value" (whatever that is) Also its one of those silly signals that they "only buy the best" or "only use the best tools" or something equally pointless. People aren't buying rolexes to check the time...
I don't think that is deep enough for the mac pro to be stable front-to-back-wise, and it also only holds 60lb which is a little weak for a 40lb machine. Can't imagine it would last long if ever rolled around on carpet.