I think in this case it's more likely that the US government wanted to have light trucks be fairly accessible to individuals that needed them, and somehow it became a cultural icon to have a pick-up truck that doesn't ever pick anything up. Now we're here and it's a hot-button cultural issue proxied as "the left is trying to change my lifestyle, not over my dead body."

I don't blame the government for not seeing a need to regulate this decades ago. Really, who in their right mind would want such a difficult to park, more expensive, less economic vehicle if they didn't need it, right?