It’s not exactly that. In the US we insist on perfect, white eggs. No chicken shit or feathers, heavens forfend! Because most Americans have never touched a chicken, let alone seen one.

So we wash hell out of our eggs, which thins the shell, which makes the egg less resistant to bacteria.

Europeans understand that eggs coming from a chicken’s ass sometimes have feathers and poop. Because it do be like that. So they get thicker, tougher, more resilient egg shells.