> To keep things short: Whenever you want to insert some text you need to switch to Insert mode. When you're done you Esc out back to Normal mode. Undo will undo everything you did inside the last Insert.
That's a more extreme version of the behavior I'm objecting to. Why would I prefer that?
Undo is for undoing an action, like inserting a bunch of text.
If you want to delete one character at a time backwards... use the backspace key?
Put something in the wrong place (probably via pasting, but it's not always clear to a screen editor if you pasted or just typed quickly)
This is worse when I'm using multiple cursors, which is usually me manually cleaning up some data.