status-declined Oct. 23, 2015 (Jon Ericson)
I find the topbar notifications very compelling; it's difficult to let them sit unclicked. My amateur behavioral psychology suggests that only showing positive changes is a big reason. It's not that this idea wouldn't be useful. Rather, it works against the original purpose of the feature: engage users when they do positive things on the sites. For a subset of people (even high-reputation users) the aggravation seeing the occasional downvote displayed prominently would be a turn-off.
#Show downvotes in the topbar notification area
Show downvotes in the topbar notification area
You know, this one: Display lost/negative reputation in topbar achievements
Big kids don't need the truth hidden from them.