It's not a scam. It's perfectly maintainable. If you aren't positive how it works, read the paper
http://economics.uchicago.edu/workshops/Weyl%20Glen%20-%20Quadratic%20Vote%20Buying.pdfNot positive how it works, but I am positive that it's a scam. No possible way for that model to maintain itself.
Why would that be a red flag? You can't get all of the 1.75 BTC now, as there are over 30 votes. You would have to share with other people.