Four primary variables: 1) Collective interest of the researchers in the topic of attack 2) Collective interest of the financiers of research on some application of the topic of attack 3) Funding for research 4) The effective tools for experiments are already invented and available (example, a microscope)
We do not do science for some high level goal of "Benefit for humanity". I love stars, I like astronomy, and when I study the stars, I do not think about how my study would impact humanity. I just study them because I find them interesting. (Studying star systems do not actually have much impact on humanity in general, mostly).
Attempting to qualify science only limits it.