That is an interesting point. There are some people who make the opposite argument. For instance, on the Jones Snowboards site they talk specifically about how the blunted nose is better for powder (including for the Hovercraft, their dedicated powder stick).
Also, the NS Cobra has a blunted nose.
I tend to think that a nice long nose kick/rocker is more important for powder capability than the shape of the nose.
A gradual upturn is what makes it work. The nose length can be short but to get a gradual upturn you will lose a fair bit of the effective edge toward the front to rocker ie. the rocker has to start near your binding. A long nose just helps you keep a longer edge in the snow so the board will handle on piste as well as off.