Because there are 16 new characters in the poll from witch 8 are more popular than Akyu, plus the Aki sisters both gaining +2/+5 ranks instead of dropping 8 places. That makes 10, 40 + 10 = 50, + 1 rank drop, probably to the new characters as well.

Also, Akyu only appears in the supplementary material, and not in the actual games.

as above said

quite frankly i dont know who you are xD