Fear sells. If a company thinks they can profit from people's fears, they'll do it. Buying antibacterial soap makes people think they've got some control over something, in a world where we have very little control over anything.
Also, we have a phobia about death in this country, so if we think we can prolong our lives by wiping out every germ in the world, we'll give it a shot.
And you're right about keeping things in context. We actually need some of the germs we encounter.
However, I don't think the education system is feeding the fear as much as the media and businesses do. The education system is actually trying to encourage people to think. What a concept!