I too am ok with ed(1), which is IIRC what you had in Sixth Edition before the newfangled ex/vi showed up. I actually prefer it as simpler.
These days, I tend to ed(1) for really quick things or bad situations, and emacs for everything else. What I find broken is that various programs have EDITOR and VISUAL, which I have set to ed and vi. But 'vipw' calls $EDITOR, despite not being called edpw. On the other hand, visudo seems to run VISUAL. Having looked, it seems EDITOR is intended to be just the editor the user wants, and then it's just more complexity than warranted. So I'd be fine with sh(1) using EDITOR, and picking ed(1) if EDITOR is not set, and everybody encouraged to set EDITOR and not set VISUAL, if indeed that is sound.
