Actually, it, in the general overview of the album, rounds the value to the nearest star. Thus, an album rated 4.46 would be classified as "an excellent addition to any prog collection" while an album rated 4.63 would be classified as "essential: a masterpiece of progressive rock." However, 4.46 is useful, as it tells you general proportions on the outset of how many people thought what (though you can find exact percentages by visiting the album in question), and 4.46 also tells you that it is somewhere between excellent and essential, generally in the middle. However, if it only rounded, there would be no distinction between 4.01 and 4.49, while the distinction is quite big indeed.
Sorry about my rambling, but that is the best answer I can give. I support the system as is for now.