help to keep the lights on during times of low Steem price performance, we are literally on the bones of our bum

We all are, but it also makes the challenges of trying to do something systemically good with the reward pool being directed by proof-of-brain and not milked by self-voting and vote selling all the greater. Every bit of payout is precious at this juncture.

I'm not really familiar with some of the other services–some may be close enough to a public service/public good they would be good candidates for SPS or upvoting of posts about them–but steemvoter specifically, I see very much as a service which offers 90% or more of its value to its customers and its customers should be the ones paying for it, not the reward pool. Others may disagree, and they are free to organically upvote your posts. But my guess is that few stakeholders in fact do disagree, or your wouldn't need to rely on the condition-of-service upvotes.