Frank, sure not that many people have Intel Macs by now (even the 30% number you mention seems quite high to me). But how many people are in a situation in which they need a specific sound editor? That should be a small-ish group to begin with. Particularly once you removed the people who want the sound editor for stuff like podcasts where GarageBand will do the job just fine and comes for free with your machine. I'd guess that the market for a sound editor is much smaller than that for an image editor as loads of people will have digital images and may want to tweak them, while comparatively low numbers have the skills and incentives to create and edit sounds.

At the end of the day it's Adobe's decision anyway. If they don't see a market on PPC Macs, well then they won't make the effort to program for it. That's just how things work...