The songs on GAF are actually very well constructed pop/rock songs but I think it's their formulaic nature which is the thing that anti-GAF people find offensive.

If GAF had been made by any other band in 1990 they would have had a decent, serviceable album on their hands. It's just that Starfish was the beginning of what The Church could do with their collaborative/jamming style of songwriting. Even though much of Heyday was written collaboratively it is still comparatively rigid when put next to the loose, flowing style of Starfish.

As Steve has said, Priest=Aura should have come out after Starfish. GAF is not a bad album in and of itself, it's just not the best example of what Kilbey/Koppes and Willson-Piper can do together.