At its root, science is about testing, observing, forming conclusions, and retesting. It just so happens that in the subject of economics you have an extremely large number of variables because of human behavior.
While concrete conclusions are difficult to come by, we should absolutely continue trying to understand things that we do not currently. Consider a future where the entire human brain could be mapped, and we entirely understood behavior. In this case studying economics and decision making would be much more realistic.
Just because our tools are extremely limited doesn't mean we should stop observing, and that very act is true science.