The hardest of the social sciences will create experiments where they try to study a single variable, like a person's reaction to a specific set of stimuli or decision making under a certain specific set of conditions. That way you can at least pretend to control for things.
It is simply impossible to do this in management. There are millions of variables. You can't know them all, control them, or do multiple runs of an experiment.
One of the more recent management fads has been complex systems simulation -- trying to do computer simulations of difficult managerial problems. This can work for logistics, routing, and mechanistic process optimization, but you can't reduce human beings to "agents" in a model.