They patented "a grid of icons" when it's literally the first way you'd think of doing the UI - basically the definition of an "obvious patent". Not to mention that it'd already been done that way many times before and was the standard thing on smartphones by that point. So both obvious and massive prior art.
For instance here's a Nokia phone from 2005:
https://phys.org/news/2005-03-nokia-3g-imaging-smartphone-sh...
And a Cingular branded HTC Windows phone from 2006:
http://www.flobee.net/wp-content/uploads/cingular2125.jpg