There are reasons to control food items entering and exiting any country. They are important reasons.
But as a general rule that is raw food not cooked.
Cooked food is generally free of any sort of pathogens that would contaminate the area.
Raw apple no, cooked apple baked in a pie, no problem.
In this case they were straining at the cooked food (gnat)and totally ignoring the fact (camel) that this person could be carrying the virus on his clothes and shoes.