Perhaps it will help to give some examples of people who don't have the badge:
- if you have not yet voted on 600 questions, you don't have it
- if you have voted on 600 questions and 5400 answers, then only 10% of your 6000 votes are on questions, so you don't have it
But if you have (for example) 2400 votes total, 600 on questions and 1800 or less on answers, then you would get it. or 700 on questions and 2100 or less on answers, and so on.
It's rare. Say a question has one answer and you vote for both question and answer. Then you would have equal number of question votes and answer votes. But often a question is only so-so, meaning I don't vote on it, but one or more answers are great, so I vote on them. And other times I do vote the question but there are 4 or 5 answers and I vote on all of them. So in general I have a lot more answer votes than question votes. Most of us do. This badge is there to encourage us to remember to vote for questions.