I like command-lines. I don't like TUIs. Here's the litmus test for whether a program truly belongs there: Would it shit the bed if its stdout was a printer?
I was going to disagree with you, but after thinking about it I don't think I do. Vim is a great program that would completely shit the bed if stdout was a printer. However, vim's interface is shit, regardless of how well it works after using it long enough. It's notoriously hard to learn, and the vast majority of non-programming users, IMX, know enough to open a file, make a modification, and save it. Vim would be b…
Also, a surprising amount of TUI apps do have at least some mouse support. Sure, it will never be as good as a GUI app since you can't scroll by less than one row, and depending on the terminal the responsiveness for resizing isn't great, but it is there when you want it.
Also, one of my favorite things in vim is splits. Whenever I use GUI editors the split support seems to be very bad. Some of the Mac OS editors are at least meant to be used with multiple windows, but I think that philosophy of the desktop metaphor is dying out and people are just writing apps to be used full screen.