Comment 2 for bug 2051371

It's never the terminal emulator (whether GNOME Terminal or any other terminal app) that decides what to print on a backspace keypress. The only thing it does is that it tells over the tty line that the backspace key has been pressed.

It's the remote party, which could be the application running inside (such as "bash", "vim" etc.), or the kernel's cooked mode handler code (e.g. if you're running "cat") that decides what to tell to the terminal how to update its canvas (such as e.g. retreat the cursor by one, print a space, and retreat the cursor again -> to achieve the visual effect of deleting the last single-cell character). The terminal emulator has no other choice than to blindly execute these instructions and update its canvas accordingly. (It cannot even tell if this requested display update was in any way connected to the backspace keypress or not, nor should it care.)

That's just the way this whole architecture looks like. You have to file a bugreport against whichever applications where backspace doesn't work as you'd expect it.