To be fair, I do not believe anyone called you a scammer because it was suspected that you wouldn't pay as promised. The reason you were downvoted is that paying individuals does not bring value to the platform and some of us value the success of platform more than $10 worth of Bitcoin.

The broader motive of the "value exchange" as you call it, is to produce a positive externality in the form of valuable content which enriches not only a specific voter, but the community and platform as a whole. Paying money to voters alone does not do that, so naturally those of us with the broader view see it as a poor value for our reward fund; therefore we downvote.

Nothing wrong with doing experiments, but for experiments to be meaningful they have to accept the possibility of an unfavorable (for some) outcome, as happened here.