(First off, I am using the image that @dantheman put at the top of his recent post on negative voting to indicate the thematic link. If this is not appropriate please let me know in the comments. )
Ok, now the main argument: When talking about "negative" or "positive" voting, the reasonable assumption is that voters have influence over the policies implemented by the representatives that they elect - be it of a country or of an organisation.
However, this influence is indirect in many respects: It is indirect in time since typical legislative periods last for 4-7 years. It is indirect in person since there might be intermediate layers of representation between the citizen voter and the top leadership of a country. But, most importantly, it is indirect in policy since voters are unable to specify with any precision the myriad of decisions that their elected representatives will make.
Hence, voting is to a large extent "imaginary" in the sense that the influence expected from the vote is far smaller than voters might want and candidates might want them to believe.
The obvious thought at this point might be to replace representative democracy with direct democracy, i.e. a system where each decision is made directly by voters rather than indirectly by elected representatives. The pros and cons of this have been widely discussed; suffice to say that a highly complex entity such as a country and the sheer volume of decisions to be taken preclude the use of direct democracy as an easy solution.
But we can catch a more promising glimpse by looking more closely at what elected representatives actually do: Firstly, they channel influence - both the influence of voters (or rather, the desire to be re-elected by them) and the influence of lobbyists, pressure groups and the like. Secondly, they work out compromises with other elected representatives, and this is how big and small decisions get made.
And it is exactly that second activity - working out compromise - that offers a way out. Until a few years ago, it was impossible for the ten or hundred million voters of a country to come up with meaningful compromise instead of fighting each other over this or that position. Therefore, elected representatives were crucial in order to cut the number of people involved to a practical level that allows compromise to be developed.
So - in my view the crucial discussion is not over voting systems, be they positive or negative, but over the art of mass consensus building and compromise development. Initial attempts within organisations such as the Pirate Parties in several European countries using the Liquid Feedback tool have been promising.
In fact, the question is whether Steemit could be used to back this type of tool ... can compromises be reached by consensus indicated by votes and Steems?