"User serviceable" doesn't imply that the user will actually perform any service. I would be willing to posit that for the vast majority of users, an ATX desktop is just as "serviceable" as a Macbook Pro. In the case of the desktop, if it breaks, they take it to their IT department or Best Buy and get a technician to fix it. In the case of the Macbook, they take it to their IT department or the Apple Store and get a technician to fix it. And the Macbook Pro is a darn sight lighter, more portable and more attractive to have sitting on your desk...