You'd actually surprised how voted beyonetta is. She was top 5 in the US and #1 in europe. I think some problems are that many people that wanted these characters didn't vote(For an example, many Wolf fans took it for granted asuming he was very likely.), many just weren't legibable, and some seem popular but aren't, they just have a very loud minority.
Also, the ballot wasn't going to pick the top regardless, it was more of picking the best choice out of those top ones. Hence why we got bayonetta.(Which I'm very glad for.)
As for corrin, well, yeah, obviously Corrin is there to promote fates. Thus was planned. But eh, I'm one of the very few that are excited for them. I could care less about represanation, given that the only juggernauts that even get a ton of reps are Mario and Pokemon, thus seems irrelevent.
Gameplay is more important to me, and Corrin and Bayonetta both deliver very well.(And Cloud, got him yesterday, character I never knew I wanted.) That and male Corrin is cute.
That and Corrin turns into a fricken dragon.