I can define a lot of things that I believe are bullshit and whose definition doesn't "map to a true/false claim" (though I don't understand what that means either).
Then you don't understand what the original author is talking about.
The essay "On Bullshit" means something very specific when it talks about bullshit and bullshit's contrast with the lies or the truth.
The point is that truth/falsity is at best an inconvenience for bullshitters, it plays no material role in the things that they say, or assert.
So, there is a whole range of possible statements that bullshitters may make that are either so squishy they don't mean anything, or are formulated in such a way that they can't actually be assessed to be true or false.
The article author, by making the claim that 'gamification' is bullshit, is asserting that 'gamification' is not an actual thing that we can evaluate.
He's trying to place the onus of explaining what 'gamification' is and what it's import/role in the world is on the people touting it.
I'd go so far as to say that 'gamification' is a fraught term, because it's predicated on a definition of 'game', and given that word's controversial past both within and without the ludology world (http://en.wikipedia.org/wiki/Game_studies ), 'gamification' appears to be a marketing buzzword more than anything else.
