Help me understand. Help me overcome my narrow, "fundamentalist" thinking. If net positive, net negative, and net neutral are not the only logical possibility, then what other possibilities are there?
If you're arguing that determining the net of something like globalization is complex and challenging, I agree, but I don't see how that proves that there are more logical possibilities than the three I've identified. Modern global civilization is extraordinarily complex, and yet we try to find ways to measure the effects or outcomes of modern civilization to determine if it has been a net positive or net negative for humanity. This is at the heart of the concept of "progress." Now, maybe you don't subscribe to this concept, maybe you reject the grand narrative of human progress, and if that's the case, well, fair enough, but I can tell you that most of the proponents of globalization absolutely do subscribe to the concept of human progress, and they have advocated for globalization because they believe it will further said progress.
If you're arguing that "positive" and "negative" in this context are inherently subjective, and thus there's no way to determine if globalization is objectively positive or negative, that's fair, but if that's your argument then it's just as valid for someone to say globalization is bad as it is for someone to say globalization is good.