Trying to make fun of someone who's being careful about what they eat is pretty insulting.
Food processing laws are there because certain bad things do happen at scale in factories & restaurants that don't happen in home kitchens and when they are personally eating things in the world around them. The laws have to protect the very young, sick and the very old with their compromised immune systems. So there are different standards for different circumstances.
There is also a matter of degree. A commercial food chef needs to wash their hands, a healthy adult person eating prepared meals by other people doesn't need to wear gloves everywhere to be safe.
Also a lot of restaurants and farms are pretty gross places, go work at a fast food place, butcher, meat processing factory and cow farm to see how gross it gets, even with food safety laws & inspections.
The hardest thing about that upbringing for her is that her instincts toward our children are very much geared toward avoiding germs at all costs. Because that was how she was raised, that's the only way she really knows how to raise our kids. Fortunately, I'm there to get them really, really dirty.
Unless your immunocomprimised or old, your body's immune system can handle the everyday bacteria that is everywhere in the world.