Lol if I could read the minds of people and know why they do, or don't do, stuff I would be a billionaire.
I can only suggest that you find the large stakeholders that aren't voting and ask them. :)
Although, I will say this: It has been said that the developers and stakeholders are just trying to take the SteemIt stake from the Proposal System. Some people have made proposals asking for a lot of money in exchange for the proposed work they would do. I personally do not feel that I am asking for much for the work I have done and will continue to do, but if others feel that it is too much they may abstain from voting.
That's the point of the proposal system though. Voters can choose to vote or not and if the proposal creator feels it necessary to delete and recreate the proposal with modifications they can do that too.
Since I feel the proposals I have are fairly priced, I will leave them active and voters can add or remove their votes as they please. That, of course, is another benefit of the proposal system and why I asked for the payout to occur over the course of the year and not all at one time; voters can always remove their voted to have the payout cease.
Well, I find the non-voting rather strange because obviously the blockchain needs maintenance and development. So yes, I understand there may be disagreements on the amount you're asking for, but since this proposal is so critical to the continuation of the blockchain, presumably there would be discussions on the price (if need be) so adjustments, if any, can happen and the necessary work can proceed.
I myself don't know how to estimate the proper amount when it comes to your proposal but I know the work scope covers some of the fundamentals for the blockchain's continuing operation so I voted for it.
I think if proposals are asking for too much, then competing offers that accomplish roughly the same work for less money will start showing up. The danger I see is if certain people get entrenched in their positions so they become irreplaceable. Antidotes to that would be transparency, more documentation, less barriers to entry, etc.