I haven't looked very deeply into the system used by Discourse, but I agree that gamification for its own sake isn't very appealing. The idea of adding a competitive element to incentivize participation seems to me to be at odds with the idea of a forum as a place for communication and sharing of information, which are essentially cooperative activities. In many cases the expectation is that the gamification system should be used in a spirit of irony, at which point it's just adding noise to the system.
I've got plans for eventually opening semi-public forum where some sort of reasonable reward/ranking system might be useful. But my current esoTalk forum is an in-house system for discussion of work-related projects. In that sort of forum, gamification would only get in the way. So whatever you end up going with, I hope it will be handled as an optional extension.
Incidentally, is there a list somewhere of features and functions that will definitely be included in the release version of Flarum?