According to Aohige, yeah it's mostly little kids and the most hardcore of hardcore who do the weekly polls.
Older voters tend to show their support by buying things instead.
Well in that case most of TOC is hardly surprising. Kids are fickle as fuck, no action=no votes. Long established series like HxH are fine if they linger around the bottom for a bit, and to a certain extent that applies for Beelzebub too. It does seem as though fans who buy the merchandise and volumes and such have "better taste" (don't know any other way to put it). Then again, Bleach sells well in terms of volumes and stuff so….I don't know, japanese kids are funny sometimes.