It's just these days we are more aware and careful, people feel...

It's just these days we are more aware and careful, people feel better knowing their rain water is clean if they rely on it for drinking.

Sure a bit of dirt in the rain water is not going to hurt you but cleaning you gutters, allowing the first rain to drain away and preventing other stuff getting into the tank means you have cleaner water and more time between having to clean out the tanks.