Will.i.am is actually a VERY, VERY, VERY talented songwriter and producer.
I don't think it was his fault that BJ was trash. It was probably Larry pushing him to do certain stuff.
He always seems to be great when it comes to producing and writing for BEP but not so much with his solo projects/work for other artists (with the exception of The Dutchess).
I doubt that Larry has that much/if any say when it comes to the actual production or lyrics of her music. As executive producer of the album, I definitely maintain that Will is the culprit for the trash that is BJ.