This is because I need a tighter visual feedback loop to confirm that the IDE has chosen the right identifiers and inserted extra parentheses and such, and so I couldn't get a few keystrokes ahead of what I see. It's nice for debugging where I only need to replace a few things in a few lines, and I suppose it might be nice if I am trying a new language and wasn't typing very fast anyways. It's not something I use regularly for development.