Why we need both voice and handwriting recognition

Imagine: you've had a hard day at work, you stumble up the stairs, flop onto the bed. You say "Computer, play Led Zeppelin II" and instantly "Whole lotta love" is blasting out of the stereo, helping to reinvigorate you for the evening ahead. Why do we need voice recognition? Because scrolling through menus so select an album to listen to (say on your smartphone), and then going through another set of menus to tell your smartphone to play via your bluetooth speakers, takes too long.

So if voice recognition gets nailed, do we need handwriting recognition? I think so, otherwise your office is going to be a very noisy place! (obviously it may lead to a revolution office working, but there are still occasions when you don't want to speak what you're writing out loud.)