Have you noticed that people in the computer profession rarely use the word "computer?" We call them machines or, disparagingly, boxes. Macintosh computers, of course, are simply called Macs. "What did you get, a Windows machine or a Linux box?" "I got a Mac."
Is it like that in other professions? Do practitioners use euphemisms or synecdoche for the primary objects or clients with which they deal everyday? Do dentists secretly tell their receptionists to "bring on the next mouth?" Do morticians work on davs (cadavers)?
Is this a way of showing mastery of the profession, by denigrating the elements of the work? Ranchers referring to cattle as doggies seems to suit that purpose. Likewise the sailor referring to a vessel as a tub. Would astronauts say "Strap me onto that firecracker?" In this usage, the owner of the Linux box exhibits greater mastery than the owner of the Windows machine.