It is absolutely the voters, and I'm one of the voters too. (Though I do vote late to reduce trending. I also haven't voted for this rules update at all.)
I absolutely believe, 100%, that there should be a none-of-the-above option when it comes to reward voting.
Who is responsible for how much voting support none-of-the-above gets? Both voters and posters.
I fail to see how you can conclude otherwise.
You won't convince me that none-of-the-above doesn't have a role to play. I simply don't agree that arbitrarily low-value content should be paid, by default, because nothing better is available. That's a cop out on behalf of posters who want to get paid without really contributing anything.
And, truthfully, your gripe doesn't seem to be with the concept of none-of-the-above at all, but with how highly it is voted (i.e. ends up on trending). So, again, take this up with the voters and/or posters who aren't posting compelling content that ends up higher on Trending, pushing burnposts down. I have voted for such content in the past and I expect to do so in the future. Nothing would make me happier than to see more of it.
BTW, SBD is a secondary consideration when it comes to burnpost and virtually not a consideration at all when SBD is below $1, which has been the case for the past year. The primary purpose and function of burnpost is none-of-the-above. The various rules for how to deal with SBD being received are there to maximize value for Steem stakeholders and avoid negatively impacting the peg, but again, that doesn't even come into play when SBD is below $1 and SBD isn't being paid out in rewards, both of which have been the case for the past year.