[riffraff]

when pair programming in person you can trivially point to a bit of code with your hand, if you just share a tmux session (or screenshare via Skype/hangouts) you can't do that and it becomes a bit awkward. Multiple cursors allow you to do this ("<hover> this bit of code" vs "the second condition on line 60, around column 40?" more naturally.

Switching control ("we can do it this way, let me show you") also has less friction with collaborative editing tools compared to classic in person pair programming (no need to shuttle a keyboard/chair back and forth).

When I started using Screenhero which allows screen sharing with multiple cursors it was incredible how effective it felt.