Even without terminator seeds, replanting seed that you harvested is not necessarily a good idea. For instance, most commercial corn seeds are hybrids, made by crossing two highly inbred plants. This means that the seeds in the bag have pretty much the same DNA as each other. Those plants produce far better than their inbred parents, and they are quite predictable in most agronomic ways.
Now, what happens when you get the next generation? When Hybrids cross with hybrids, the actual genetic makeup of the offspring will produce quite a bit more variation. With that increased variation, come less average yields. So even if a farmer didn't sign anything that would stop him from planting the seeds, chances are that a farmer would have higher profits by just buying a bag of seed anyway.
Not so much for Soybeans though, but that really is a place where Monsanto has pretty much a monopoly: Roundup protection increases yields so much that non-GMO soybeans are barely planted, because they are far less profitable for the farmer.
> because they are far less profitable for the farmer.
That really depends on the market you are selling into. It is definitely not a hard truth. For instance, we only grow non-GMO soybeans on my farm because they are quite a bit more profitable and seem to get even more profitable each year. We won't even consider looking at GMO soys until that dynamic starts to change. Farmers in other markets might not be selling to the same customers, and therefore might not be able to see the same margins on non-GMOs.
At the end of the day, it all comes down to what the consumers are buying. With the tight margins in farming, you'll be out of business in no time if you aren't growing exactly what the customers want.
Terminator seeds have never been used except in research. It says that in your own link. Monsanto have also made commitments, including to the courts in the USA and Canada, not to ever use the technology.
Not after terminator seeds are used.
http://en.wikipedia.org/wiki/Monsanto#Terminator_seeds http://www.globalresearch.ca/the-seeds-of-suicide-how-monsan...