I'm Considering a Boycott
It's possible to make a case that GMOs “aren't necessary.” If a business rejects GMOs on that ground, it's as though they had a mouse infestation problem and controlled it by acquiring brown cats, yellow cats, and gray cats. (Black cats aren't necessary.) Black cats might not be necessary to control mice, but if they're excluded, one might wonder what other superstitions are being taken seriously.
Besides, such a rejection implies they're selling to idiots.