It is certainly a false dichotomy, because you paint it as a decision between GMO and conventional non-GMO farming. But as in all false dichotomies, there are more alternatives.
And no, that is not how decisions are made. You don't stand stupidly and consider if you should drive your car to work this morning or not, without at the same time taking into account the alternatives and their consequences. How long would it take to walk, how is the path, the weather? Are public transport available, how much does it cost, how long would it take?
So there is no dichotomy for the decision maker either.
At any point in the decision making chain, in general, the decision is "should be do this new thing, so should we not".
So it really is a dichotomy, at least as far as the decision maker is concerned.