[gbrown]

I'd propose that has more to do with the headlines than any of the actual science. Model tweaking is exactly how a lot of this works - models are supposed to reflect reality, so part of how we explore them is to find out what models fit past (and predict current/future) reality. This is both intuitive, and based on theoretically sound inference (see Approximate Bayesian Computing for an exploration of the connection between simulation and formal inference).