That sort of simulation is entirely worthless because it doesn't account for changing behavior, which is the entire point of it.

Downvotes absolutely should hit the author (as well as the other curators, but not to the extent of favoring the author). The fundamental goal of both upvotes and downvotes is to pay authors in accordance with a stake-weighted consensus of value contributed. Downvoters are contributing their opinion into that consensus process that the payout to the author is too high.