For me in creative writing, "what happens next", tends to appear in large batches of inspiration, and I really want the high bandwidth of a keyboard to make sure I can record all/most of it before it decoheres. It's a personal thing. I always respect those with the patience to draft longhand. :)
Fair enough! I'm writing mostly things of a short nature -- this class focused on satirical writing, so under 1000 words. I've also done some sketch comedy, so perhaps five pages. It might be very different if I were writing anything longer, that didn't require tiny pieces to fit together.