Most households do not follow basic food safety handling practices. Many households prepare some form of protein for many meals. Protein is often comprised of poultry or beef. Both poultry and beef have very high levels of contaminants that should be kept away from many surfaces but those surfaces are not wiped or properly sanitized after preparation.
Most people are pretty lax about what they eat and how they prepare the food that they eat. So it would be a good guess to say that most people are not cleaning their cutting boards well enough and are not following the correct food safety handling principles when they cook.
No, I do not think that proper food safety handling principles are followed in most households, because most people are stressed out, and busy families end up cutting corners. People eat food at home that would be considered way out of date at a restaurant. People have a lot going on and food safety falls by the wayside.
I do not believe the proper food safety handling principles are followed in most households. This is something that should be taught to all high school students given its importance in the real world. I think there are many people who fail to understand the importance of these practices, but they don't follow them because they aren't fully aware of them.