they did it the same reason a website would rate a game 3 and a HALF, out of 5.
because 1,2,3,4,5 was handicapped, not enough range to give an accurate enough of a rating.
so basically out of 10.
same as game. when the differences in the thousands of weapons,armors, damages, defenses appeared to make almost no difference, now you can actually see the difference.
people who could possibly think it "ruined" anything are just stupid and dont understand numbers at all.