@JTT,
Even easier would be just to display the total positive votes as the primary number. Or to separate the questions from discussions in all views so that questions aren't rated together with discussions.
able2know site actually started as fluencynow.com (now someone else owns this site) for my English students, so I obviously love having the English questions, but I get why the more discussion oriented people vote them down.
To me, the big solution is to separate the site more between the discussions and questions but I think I'll wait till the next topic type to do that as it is a bit more of a disruptive one to the current pattern. In the meantime we'll work on different vote aggregations and reworking it to use the positive votes as the primary number.
That way, it's just less positive on the grid and never negative.