Next time you are in a game, start a vote/survey about something. Watch how many votes you require initially, and watch how it increases with each no vote. In a game with 20 people, 6 yes', 5 no' and 9 abstain, the vote will fail. Initially when you start the vote it will require 10 yes' to pass, but with each no that figure increases. With 5 no', you would need 15 yes'.
To be honest, just having abstain and no counting as 1 vote against, and not increasing the required yes' would be a more than fair way to do it. Even with this system, the vote is weighted towards no because the abstains effectively count as no. In the event you have more than 50% yes', then the vote should absolutely pass as you definitely have more than 50% who want it, but could have less than 50% who don't.