The situation is paradoxical because, as educational psychologists would say, no learning can take place where there is a presumption of knowledge. The challenge for the academics is to find ways to relate theory to the workers' experiences in the field, without assuming an appreciation of the value of the theoretical approach. This could be an objection to too much theory rather than to theory as such. Another possibility is that the instructor is too vague, and there is no reference to students' personal experience. Finally, 'it's too theoretical' may mean 'too complex'.
Complexity is a feature of the phenomena most theories aim to explain.
The objection that a theory is too complex is a serious one, as a key criterion of a successful theory is that it explains complexity in simpler terms. Consider for example, the complex phenomenon of humanitarian assistance itself. The usual explanation for why aid is given to the destitute is reference to the virtues of generosity and compassion. There are two problems with this kind of explanation. First, it does not explain why these virtues are not manifested in all cases of destitution, but only in some.