If a bunch of contributors vote 'no' and pull their money then how do I improve the project and get them onboard again if it's going to be OSS? With shareware, I can improve the product and catch them on the next release.
Contributors can only pull money if it's been more than 30 days since they made the contribution. After that 30 day holding period, they can walk. We've considered playing with that number, or letting it be variable.
Contributors don't have great incentive to let an election fail; if it does, they don't get any software (other than whatever demo the developer posted). While I'm sure there will be cranky contributors here and there, hopefully we can factor them out to some extent in our election process. At the macro level, people are going to want the project they contributed to released.