GMO LABELLING IS NOT JUST ABOUT SAFETY.
Of course it isn't since there are no known safety concerns of GMOs. It's about fear mongering and irrational people that don't understand scary words like "GENETIC".
What's "deficient" is knowledge of which products are using a technology that people object to on, for example, the grounds that Monsanto's use of patented GMO crops are polluting neighbor small farmers who are then inadvertently find themselves in trouble for patent infringement.
Not all GMO crops are patented under abusive corporations and not all GMO crops can cross-pollinate. Unless we label all products that come from unethical corporations, no reason to start here. If we do start here, we should label them "Unethical corporation food", not "GMO"
Another reason is people don't like new technologies forced on them whether they like it or not.
Do we give them that choice for other technologies? Of course not! If some crops are grown with a new type of fertilizer or processed in a different way, that's not indicated in any way, should we label food with "Harvested with Mark-12 combine harvester" as well? What about just a generic "Brought to you by new technology" rather than just the specific case for GMO
They know if they label GMOs some people won't buy them because of it.
This is exactly the reason why we shouldn't have mandatory labeling - people won't buy products they see have scary "GMO" on them, but they aren't doing that for any reason.
Now if food manufacturers want to label their foods as "GMO-free" or "Asbestos-free" or even "GMO", they should be free to do so, but we shouldn't be passing laws requiring food that comes from a different process be labeled because some people don't like scary words.