True, 5 wouldn't do anything, but I can write a Python script in a few minutes that would keep creating alts as fast as the server would allow for weeks. Hundreds of thousands of users. Then I can single-handedly affect the outcome of any poll.
It wouldn't take too much more automation to have them generate realistic looking comments using AI so they appear to be active users. Actually, how can you tell that I'm a real person? Maybe I'm a bot that can produce realistic looking conversation. :P
Electronic voting is a difficult thing to do in a way that is secure and accurate. I do think the idea of having a say in how the server works is a great idea. But it's one that is tricky to implement correctly.