This legislation doesn't appear to apply to Penn State. Despite its name Penn State isn't a state-owned school. It's "state-related", which basically means it gets a lot of state support but is independently controlled. The legislation appears to apply to PASSHE, the collection of true state-owned schools (which are generally smaller teaching colleges). I suspect PASSHE has a lot less land at its disposal than Penn State does.

Much more likely it's simply because when you pull your fingers apart the system immediately knows WHERE you want to zoom in on -- namely, on whatever location your fingers were initially over. If you wanted to make "moving fingers together" indicate zoom then the system is left guessing which point of the picture you want to zoom in on... presumably it would be whatever point your fingers are converging towards, but that can be hard to estimate accurately (since your two hands might not move at the same speed, or even in a perfectly straight line).