If scientific validity were our lone motivation, than yes, it would make sense to ignore these "slippery concepts," as you describe. But this is not the case. I

If scientific validity were our lone motivation, than yes, it would make sense to ignore these "slippery concepts," as you describe. But this is not the case. I, for one, dread the mechanization of human behavior, even if it may seem accurate. The same goes for others, too. In general, people will not reduced themselves to mere cause and effect; they want to exist as more than than. Having verifiable evidence against my beliefs means nothing, because my intention is not factuality. That's why creationism and evolution may coexist in the theologians mind. And that's why the utilitarian ideology will never become widespread. The sciences are valuable in all tangible senses, but these "models," as you describe, are just that - models. And I feel no obligation to model my existence. Honestly, I prefer not to understand myself. Life's more amusing while unpredictable.