Luta Not necessarily. I mean you could have a voting per category but would also need a minimum number of votes for it to pass. So even if there were votes in the "Other's" category but if total votes didn't reached, for example, 500 votes, then the poll is null and void.
I think this system will give a chance for novel on each category while making sure there is actual interest in each category.
Syosetu, which is the biggest jp webnovel scene, even changed how thier ranking system worked. Previously all categories are ranked in a single system. But they had to change it becuase the ranking system was dominated by 1 genre and it didn't give a chance for other categories to get the exposure needed, which was the major complaint