Well, if in 4e the GM ignores the treasure parcel rule then the game will tend not to work, as its maths will break down.I saying folks dislike the entire concept altogether, not that there is some mechanic problem that needs to be solved with it. It doesn't matter if the game tells you to, folks don't want to be told that. Also, no this doesn't make 4E bad, this is a matter of taste.
I think it's useful for a rulebook to point this out rather than keep it secret!