If amateur aircraft didn't look so good we could get away with euphamisms that get used on terrestrial vehicles. When some guy puts a Dodge Dart body on a Bronco frame that's lifted three feet everyone knows it's not standard.
But amateur built aircraft usually don't look any different from spam cans to the uneducated eye.
Would I let my kid ride in an amateur built aircraft at an EAA sponsored event? Yep, without a concern. Do I think that somebody else should know that they're about to put their kid in an airplane built in a garage? Sure.
When cars or boats break down they usually just roll to a stop. Not so airplanes.