I find myself willing to spend more time/thought crafting a response to an article which I think will be read by more people. For example, I'm just pounding this out stream-of-consciousness style since I know it will only be read by those involved in this subthread, if that. Why not do the right thing and focus on thoughtful, well-written comments for their own sake? Because I have the karma carrot dangling in front of me. I feel like gamification has in this case removed my motivation to do what is most beneficial to the site.