Do you blame the owners of the railway stations for the nazi's deporting jews to concentration camps en masse through the use of trains?
War was declared. Garrosh invaded Ashenvale full-time. Strategic decision was to split up his offensive attention in the north (Ashenvale) to having to defend his rear (Southern Barrens). To this end, Theramore was used as a port. A road was built and passage was given, but no forces were trained in Theramore.
On topic: Love the short film. Music was okay. Would've liked to see more of the tension in the Horde ranks and Baine's / Voljin's disagreements with Garrosh, but I realize how effin' hard that would be.