That's not a refutation, that's a goalpost shift.
In the real world today, you can't separate transgenetic modification from intellectual property and economic practices, when the intellectual property is technologically enforced in the transgenetic modification.
Great, you're parents and scientists. I'm a parent and a scientist too. But I understand that many of the arguments against GMOs have nothing to do with science (at least biological science) and everything to do with economics and human rights.
Just because something involves biology doesn't mean that arguments about it can be reduced to that.
You seem to hold the false belief that only GMO plants are patentable.
In reality, the US Plant Patent Act is from 1930. The First plant patent (in US) was granted in 1931. Everyday examples: Honeycrisp apple was patented in 1988 (so expired in 2008). 20 different mutant cultivars of Fuji apples are patented. Over 1000 plant patents are granted every year, and these don't go to only GMO plants.
As for terminator seed, this is a valuable technology that addresses concerns that transgenes could spread into the environment. It's also quite irrelevant to any crop that relies on hybrid vigor for yield; F1 seed must be specifically developed from inbred parents, thus no seed saving is possible. In this context, a terminator line would only serve to protect the environment.