I also usually have dozens of terminals open, though my workflow is probably different than most people on HN. I do 3d graphics on linux, so I have a separate desktop for each session of Nuke, Maya, houdini etc that I'm working on, each with a few associated terminals.

I very much dislike using things like tmux or even tabs in terminals, since I find it much easier for processes to get buried and to forget where everything is. It's much easier for me to have separate windows open so I can see everything that's going on at once.