Lobbyism and unresolved issues with intellectual property laws in my case. It has become a self fulfilling prophecy for proponents. I am not fundamentally opposed, but it has to show to have very tangible benefits.

In Europe there could be application where we could reduce herbicide deployment, it is on ridiculous levels. But again, it must have advantages. Some arguments say it would increase yield, but these are unsubstantiated from the data I have seen.

The chlorine chicken is another pop-discussion. I think it is chemically safe and protects against salmonella. Still, allowing usage will probably severely worsen the treatment of chickens, so there are peripheral issues that doesn't criticize the tech itself.

The market situation of producers is dire. Retail sets prices and the current strategy is on automatism to cheap, cheap, cheap. We had that with meat and the end result is questionable. This isn't a problem intrinsic to the technology, but third parties may become benefactors without actually improving the situation.

Europe due to its density has higher crop yields than Canada or the US for example, even if they don't employ GMO. Sure, necessity made sure of that, but again, benefits must be transparent and I don't need another large corp in my food market. And GMO doesn't really perform enough to warrant being uncritical.

Fear of unintended long term consequences which can't be undone.

Most practically used GMOs are engineered to increase resistance to herbicides, leading to their environmental proliferation. It aims for the common profitable agricultural practices, which are destroying the topsoil, to be turned up to eleven.

I don't know of any truly sustainability-oriented GMO research, without serious intellectual property baggage. I consider golden rice to be just a marketing gimmick - an exception that confirms the rule.

Lack of trust in giant food corporations, who rarely focus on health benefits, and make decisions based on what reduces benefits. High fructose corn syrup anyone.

Fear of the "artificial", when selective breeding has been a feature for decades.

The pro-GMO lobbies pushing too hard.