Because they did not show they used any methodological approach that we don't know for the past 30 years.

And according to the PR they did not use gurobi (or any sota mip solver), just their in-house lp solver in combination with shortest path algorithms and the fix-and-optimize heuristic.

Likely your particular use case will not fit their model anyway (for example you may want to consider contracts of affreighent along with leasing entire vessels).

So yes, or scientist and gurobi will definitely win.