Among other things, terminal based programs support flexible remote workflows via ssh and tmux.
Edit: It's slightly off topic, but it might be easier to understand the draw of terminal based interactions in the context of a larger toolchain and workflow. So for example: ssh for remote access, tmux or Emacs for session management and program tiling, ranger or similar for file management, and Emacs or a Vim equivalent for text editing. Mainstream DVCS and build automation tools all provide full functionality via command line. A terminal based spreadsheet program is an obvious fit for such a toolchain.
You can use VNC/RDP to remote into a graphical session. Graphical vs. terminal are both arbitrary binary streams over SSH, the computer doesn't care. There's no advantage to the terminal based one other than maybe less network utilization. I'd resort to that if I were traveling and only had my mobile phone's data as internet.
> You can use VNC/RDP to remote into a graphical session.
I didn't mean to imply that you couldn't. Rather I aimed to provide a broader sense for why someone might find a terminal based spreadsheet program useful.
> There's no advantage to the terminal based one other than maybe less network utilization.
I have to strongly disagree here. My experience with remote graphical environments, even on a wired LAN, has been less than satisfying. I suspect that a large factor for me is the latency; it doesn't take much to make a GUI feel "wrong" to me while a text based interface will just feel slow but not really bother me.
On top of such personal preferences, consider the overhead of running a graphical environment in every container or VM you might happen to make use of.
Edit: It's slightly off topic, but it might be easier to understand the draw of terminal based interactions in the context of a larger toolchain and workflow. So for example: ssh for remote access, tmux or Emacs for session management and program tiling, ranger or similar for file management, and Emacs or a Vim equivalent for text editing. Mainstream DVCS and build automation tools all provide full functionality via command line. A terminal based spreadsheet program is an obvious fit for such a toolchain.