A deadline gets a writer's work done done better and faster than any inspiration, if only because inspirations don't always come, but the deadline is always there.
A deadline is, simply put, optimism in its most kick-ass form. It's a potent force that, when wielded with respect, will level any obstacle in its path. This is especially true when it comes to creative pursuits.
There's nothing an artist needs more - even more than excellent tools and stamina - than a deadline.
I don't need time, I need a deadline.