Philosophically speaking, this is a manifestation of the is/ought distinction. It's not a logical fallacy, it's a (possibly problematic) invocation of a value system, which cannot be reduced to (or derived from) pure logic or empirical observations.
The question of how to create genetically modified organism (GMO) is a purely scientific one: practical investigation using technical knowledge derived from our current best understanding of the material principles of biology. It would be perfectly possible for scientists to work on the development of GMOs without any societal ramifications at all: intelligent, focused people scratching way late into the night merely to advance the boundaries of human knowledge. I doubt Newton envisioned all the uses physics would be put to when he invented the Calculus; if he was a typical scientist, he was far more interested in the puzzle itself than in the derivatives (pun intended) that come from solving the puzzle. Likewise, I suspect most GMO primary researchers are more interested in questions like:
- Can we do this?
- How can we do it?
- What are the limits, and how can we expand them?
than in the subsequent question of what we should do with GMOs in the greater world. A scientist's job is to get us from 'impossible' to 'possible', and once a scientist has gotten to 'possible,' she is (more likely than not) going to wander off looking for some new impossibility.
However, once we have these 'possibilities' we have an entirely new question of value. These concern questions like:
- What can these possibilities do for us?
- What values can we attach to them?
- What are the consequences, good and bad?
Science has absolutely nothing to say about that. Scientists might genetically engineer a tomato the size of a Prius and covered in pink and green polka dots, but scientists can't tell us whether a pink-&-green-polka-Prius tomato is a good thing or a bad thing. It's just a thing they can make. People have to decide whether they value such a thing for reasons of their own, and they are likely to squabble about it.
Just be cause we can do something, doesn't mean we should do it, or that we shouldn't do it.
The problem you're seeing is that GMOs (the scientific thing) are mostly attached to giant corporate interests, and the values that drive giant corporate interests are often at odds with the values that drive private individuals. Corporations value economic hegemony; private individuals value an assortment of personal concerns (e.g., health, safety, nutrition, choice, independence, etc). These values come into conflict. If in fact it is the case (and I'm not suggesting that it is, just playing the devil's advocate) that GMOs only serve the values of the corporate world and actively undercut the values of the poor and disadvantaged, well... that would be a good argument that GMOs should not be used that way, and possibly that GMOs should not be researched at all (if there is no way they can achieve a more balanced satisfaction of values). Why would we follow a line of research that will only hurt people? To give a hyperbolic example, it would be perfectly possible to research ways to increase the effects of anthropogenic global warming — scientists could certainly study how to maximize greenhouse gasses in the atmosphere, if they wanted — but would we want to allow that line of research?
Corporations often make the assumption that the mere fact that they can do something, and can make a profit off it, is sufficient to guarantee that this 'something' ought to be done. It's a restricted, exclusionary value system. While I wouldn't say that the argument pointed to in the question is well-formed, it's certainly valid to contest such a restricted value system. It's nice that scientists are capable of separating scientific research from sociological values, but you must recognize that the sociological values can't be ignored, because everything one does implies a value system. Ignoring arguments like the one pointed to effectively imposes the corporate value system on everyone, by default.