Nature is out there randomly mutating genes without any oversight. We need to test each plant for 100 years to make sure it didn't have any dangerous mutations.
A somewhat specious argument, as many foods have undergone the ultimate trial of sustaining people for millennia.
The species in general have. I think you'll find most modern strains have not been double-blind tested for a century.
Modern dwarf wheat strains, for instance, date from the 70s or so.
An excellent argument for being dubious of modern cultivars.
If people are willing to apply the same standards uniformly, I'm OK with it. I suspect that's not actually the case for most people, though. GMOs are seen by many as a special case deserving of infinite scrutiny.