User blog comment:Plattenum/My Lucky 7Wizards Week/@comment-9970378-20140702234903/@comment-9970378-20140705004443

It's unfair because you gain an advantage by having a secondary account that more or less works for you. If you made 500 alts and voted up your wizards style everyday that's unfair to others who have to gain votes by being nice to another or picking out a nice style. It more or less games their system.

I'd assume they're doubled just as a chance reward. Just like you can get XP. As for why, probably just because it's a nice touch to help.