probably best to read it while entirely mentally clear. But to answer the question,
A) It will let people tell at a glance how many mods it has gotten (very important to MAT/BAT)
B) Allow people without modding experience to still show their support for a map,
C) allow popular maps with fewer mods to stand out, and vice versa, allow highly-modded but unpopular maps stand out as well,
D) make people feel like their kudosu means more - they can have their opinion mean much more to a map's popularity if they're an active modder, or horde kudosu anyway.
i think those are the 4 main ones