You are right about speed. However, I would like to have handwriting simply for symbols and drawing (i.e. mindmapping). How are you going to enter math formulas faster with a keyboard than a pen? Same goes for marking and annotating things. IMO, precision and speed for marking/annotating is pretty bad with iOS.
But I don't see how apps like Omnifocus can make use of it.
You'd need a thin stylus for that, and Apple doesn't ship one which means they're not going to built it into the OS.
But surely it wouldn't be too hard (where too hard means technically infeasible) to create an application based on hand-written input (Graffiti or Rosetta/Inkwell-type technologies).
But I don't see how apps like Omnifocus can make use of it.