I noticed after the fact that I had composed an inward-leading spiral of black branches - it brings your eye in and back out of the center of the image, passing through the in-focus and out-of-focus blossoms.
Yeah - I think it would be very boring if everything were sharp, or if there were even an obvious plane of sharpness. This way you have to look around the image over and over again to find specific areas that are in focus.
Great photo, and I agree, if everything had been in focus it would have ruined the image. Shots like this remind me of two things. First, colour is GOOD for flower shots (especially muted colours), and two, sometimes it's better to just point the thing and fire at what may be a good shot, rather than fussing around trying to MAKE a good shot. My eye goes right to the center, where it's supposed to go. Very well balanced composition of a subject that actually had no inherit composition.