Many years ago Apple introduced the Mac Mini, a lightweight desktop computer where you brought your own keyboard and display. Unlike other Mac's, it was a simple box containing a logic board, memory, disk, DVD drive, USB, FireWire, and DisplayPort interfaces. Speaking for myself, the Mac Mini is attractive because its power requirements are miniscule (30 Watts or so), the box is small meaning it doesn't dominate our desk space, and you can choose your preferred keyboard, mouse and display. Unfortunately the current Mac Mini is suboptimal, since it's suffering from Apple's policy of non-repairable computers, and the design hasn't been updated in years.
The Mac Mini concept as a small box, low energy requirements, fitting into any desktop situation, is attractive, even if the current implementation is not attractive. Other computer companies have not been sitting still, and several have implemented similar computer designs. In particular the Intel NUC's are almost directly equivalent, and do not come with the hindrance of being Windows computers.