I suggest that one especially insidious sort of hammer is the idea that you know that other people's motivations all fall into one disreputable category.

Examples are Freudians (possibly less sophisticated than Freud) who think it's all about sex (this one is no longer fashionable), Marxists who think it's all power relationships, it's all explicable in terms of hypothesized hunter-gatherer optimization, and the recent idea that it's all status signaling.

The thing is, people are almost certainly less reality-based than they think, but that doesn't mean they're all illusion-driven to the same extent in all areas or for the same reasons.