Many new users will simply close their eyes and go on upvoting regardless of why they are or for what they are upvoting. It is because that they want the badges. So why do these two badges exist?
Short answer, not sure if the community agrees with me on this:
While I would encourage people to vote no doubt, and voting indeed is important, I'd like to stress at the same time on:
If you vote, be aware of what you vote for or against, and why
That means you have to have at least looked quite well into the answer and/or question, and in case of an aswer you have good reasons to assume the answer is good, preferably try it.
30 or 40 votes per day seem like a huge amount to me. They would take me a day's job to make. IMO too many to make a reasonable qualitative decision per vote. Not sure how these numbers were chosen, while at the same time only a few people do more then 10 reviews, as a comparison.
I am pretty sure I will never get these badges.
When I noticed the vox populi badge, not long after after creating my account, I decided I would try to get it, since I had some free time.
I took a sort of tour of Ask Ubuntu and found really great questions and answers deserving my upvote. Probably the most helpful part of that was finding some canonical questions, key landmarks...
Since then, I've never gone out of my way to use up my votes, but nonetheless I very often run out of post votes, comment votes and sometimes even close votes, just in the course of my participation.
I think the badges exist to encourage us to vote, because voting is how the site is curated of course, and also to help us gauge how much we should be voting; a lot, but not too much.
Personally I think the badge served a good purpose in my case :)
I think, in general, if people care enough about the site to want to get badges, they will most likely care enough to vote in good conscience.