I don't think the length of someone's nails determine their ability to be clean. No different than wearing a different style of clothes does. You have to trust that those who work in food service are professional enough to adhere to the rules and regulations that keep us all safe while dining out.
Restuarant workers wash their hands more than anyone. There is no link between long nails and sanitation. Servers also never touch food. It sounds like you have a personal issue.
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