Science doesn’t ban things with questionable data from poorly designed studies when other studies say the opposite.
Science doesn’t ban things because of some other problem where a causal link hasn’t been proven.
We already have a “default deny” system in place. Unless you have data saying it’s safe (according to regulations), a chemical can’t be used as a food additive.
Edited to add:
GRAS definition....."the use of a food substance may be GRAS either through scientific procedures or, for a substance used in food before 1958, through experience based on common use in food Under 21 CFR 170.30(b), general recognition of safety through scientific procedures requires the same quantity and quality of scientific evidence as is required to obtain approval of the substance as a food additive."