We're living in a sanitized world....?

Has anyone stopped and thought that maybe all of the sanitizing we do to our children and animals, wont actually help them....but hinder them. I know that my grandparents and their children and pets survived just fine without Purel. I think that by sanitizing our hands before we touch anything and anyone is wiping out the "good bacteria" as well as the bad. Why does everyone think that if a pup has all his vaccinations that he can't go outside? Or if he does, 'make sure you have people sanitize their hands first.' Pups...Kids...they need to be exposed to build immunity, hence the MLV (modified live virus). I just feel this is huge recipe for disaster.