Who I vote for in a multi-option election is a bit different than petitioning to have the actual vote. There are definitely analogies, and they do complicate the issue.
Last time I voted, my identity was checked. I then SIGNED my name stating that I was voting. That information is probably public. However, the manner in which I voted (Republican, Democrat, or write-in) is not.
Just because we can surmise how a petitioner voted when they petitioned the government to hold an election on an issue, does not mean that we know how they voted in the booth. Admittedly, it seems like you could predict the vote with 99% accuracy. You could also predict my vote with decent accuracy by looking at my political party registration and knowing that I voted. It may be less accurate, but it could be surmised all the same.
The government requires a threshold for the action that was taken. Having this information open keeps the government honest on whether or not the ballot should even include the question that the petitioner worked to have placed on the ballot. There are no 100% guarantees on how anyone voted, and there's no foolproof system to be sure that there isn't corruption in the system, either. However, this really isn't too bad, either.