I think its just a marketing ploy. 100% organic sounds better to the consumer. If a seed comes from a plant grown with chemicals, some people might not consider that seed "organic." I wouldn't get hung up on that though, a seed is a seed.
thats what i thought... but then technically wouldnt u have to also look at all previous plants grow methods??? and so on and so on... great great great grandpa tomato plant might been on them chemicals! haha 99.97% organic