Yes, and...

When I buy from a local farmer I expect to wash my produce thoroughly, and if his product makes me sick I can come back later and complain to his face. If that doesn't fix the problem I can probably get him excluded from market participation in the future.

When I buy salad in a bag* at the supermarket, I assume it's been cleaned. If not, a lot more people than me will get sick and we have little power to make the faceless company change their ways.

*Just an example. I don't buy salad in plastic bags because I think that stuff tastes like cardboard.