Why are First Principles/Theories Needed?
The reason given in the paper why principles are needed is that corporate management and project management are different and especially that these first principles explain why a margin of surplus is needed in projects. Also, in the paper's Introduction, it suggests that the proposed principles would provide a universal reference basis for a set of practices.
We agree with both of these types of reason, explanation and basis for tools and practices. However, we see the need for an explicit theory of project management arising also from several other arguments, as discussed in our paper to the Research Conference. One outstanding benefit of having a theory is that its validity can be checked and discussed. Another benefit is that a theory makes it much easier to teach and learn the subject. The learning science has found that experts organize their knowledge around big ideas - conceptualizations and/or theories, if such exist. Thus, providing theories to students pushes them along the (initial) step towards expertise.