I think there's almost zero chance we'll end up with just voluntary donations.
The only reason we're starting with voluntary donations is because we didn't have a good system in place for deciding what other sources to use until we had the Steem.DAO in operation.
From the polling results, it became clear that there wasn't a large enough consensus to make a decision via a simple poll in such a way that wouldn't leave a lot of people feeling cheated by an unfair decision-making process.
Steem frontends can add in a obligatory stake based vote on this decision with a 1 week timer. Cant log in without voting on the proposal. You can fork in a obligatory referendum type decision making process for major changes with the DAO youre doing.
Think of something....
Leaving it on people to donate part of their funds is a very rosy way of seeing the world. Though i do appear rosy, my outlook is very mid-range.
Glad to hear donations arent the expected end game.
It's not so much a problem of getting people to vote (I think it's fine if people don't have enough opinion that they don't want to vote on the issue, in such a case I don't think they have much reason to complain if the result isn't to their liking).
I'm more concerned about people that DO want to vote, but end up unhappy because they are concerned that the poll choices were created in such a way as to tilt the decision in favor of one option over another, which is pretty easy to do unless you have some kind of "approval based" poll where you can vote on multiple options, and where the allowed options are "open" to be proposed as options by anyone willing to pay a reasonable fee to make it an option.
This is always an issue. There is no way around it which is why i always emphasize going back to stake. There is no 1 option over the other, there is only what the majority stake wants.
I have been following the Steem Alliance (to avoid confusion, it has nothing to do with this.) thing for a few weeks now and once ive seen a individual with something like 500 SP speaking as an authority and over Ned, Fyrst, Aggroed in the voice chat, i quit the Steem Alliance discord immediately and never looked back.
My point is that there will always be those that will be unhappy, loud, etc... but we can always look to stake when making these tough calls.
Thats your basis for any poll you might make.