This more reasonable side of the anti-GMO argument tends to get drowned out and dismissed when people see the pseudoscience 'natural' health arguments brought out front and center. It's pretty evident that arguments for restraint for reasons of long-term sustainability take a lot of effort to get any traction, especially when fighting profitability.
All this to say, the GMO debate, like everything in life, is not as simple as most people tend believe. It is something that should be proceeded with caution, but certainly continued. This I think is where I think the almost religious anti-GMO fervor really causes harm, in the same way anti embryonic stem cell research causes harm.
Move fast and break things is a great slogan when the systems you're moving are relatively simple and the consequences of breaking them are relatively minor. Global ecology is an extraordinarily complex system that we don't fully understand, and breaking it can cause real and life threatening damage to the people of the world. Not to mention the fact that reverting negative changes operates on the same time scale as the original negative change. If it happens that GMO breaks shit, you can't just submit a patch and have things working again in a couple hours.