TomTom's 320x320 display is optimized for 320x320, I think,, not just an afterthought. A Google Image search has a number of 320x320 screenshots.

Still, I'm not sure what your complaint is. They have to make a 320x320 screen somehow. There is by definition less screen area. How does having to deal with that restriction make them "PPC-centric"? Regardless, they've been making TomTom since before 320x480 Palms were available. Is the fact that they used that extra real estate once it became available what pisses you off?