With regards to 'seed slavery's, how can farmers be worse of than they are now? They can always go back to the normal seeds if that is cheaper.
Regarding resistance, you could make the same arguments for any pesticide.
Moreover, this is about outlawing a technology. That should only be done if that technology forbid is harmful to the environment or public health. The farmers can then decide whether they should transition to other crops. That should not be imposed from above.