Simple
* Even if you take a mouse, keyboard and display into account, nobody's forcing you to buy Apple peripherals, especially the display. You can get a USB mouse for 10$, USB keyboard for 15-20$ and there's always an LCD display on sale somewhere for around 75-150$. The philosophy of the Mac mini, however, is that you probably already have at least a USB mouse and DVI/HDMI display if you're a potential switcher. Strangely USB keyboards are still semi-rare for some weird reason.
- The low-end Mac mini is half the price of the low-end iMac*
- I don't like to be forced into a display size because of my CPU/GPU choice
- I don't like glossy displays
- I can upgrade the display whenever I want without having to change the whole computer
- More portable if you have a spare LCD at the other place where you're going (ex: work vs home, home vs friend's house, etc)
* Even if you take a mouse, keyboard and display into account, nobody's forcing you to buy Apple peripherals, especially the display. You can get a USB mouse for 10$, USB keyboard for 15-20$ and there's always an LCD display on sale somewhere for around 75-150$. The philosophy of the Mac mini, however, is that you probably already have at least a USB mouse and DVI/HDMI display if you're a potential switcher. Strangely USB keyboards are still semi-rare for some weird reason.