In addition to being in agreement with several of the other reasons mentioned here, I do most of my development on a netbook, and I find it easier to just have

In addition to being in agreement with several of the other reasons mentioned here, I do most of my development on a netbook, and I find it easier to just have a single maximized terminal on a desktop, and use Tmux to manage my 'windows.' [ Also more of a Linux thing, but is perfectly possible for X11 to crash without the whole machine going down, and my session remains unharmed. ]