Thank you for your kind words!
There is a backstory, but it didn't make it to the game because of the lack of time. The company is actually getting a lot of funding for the submarine train, because it is efficient, fast and reliable way of transportation. The same technology can be also used for military purposes, and that is the real reason why the company wants to develop the technology, though the public doesn't know that. The player character knows of their plans, and he also knows that the company is the biggest military drone manufacturer. If the development continues, the company could gain control both in air and underwater. He plans to destroy the train making it look like an accident, hoping it will freak out the public and cut the funding back dramatically.
Like Hindenburg was a propaganda symbol for the Nazi-Germany, the train also has propaganda value to the company. If there was enough time to do it, the ending would have revealed that the accident dented the public image of the company, because it has put much effort in convincing everyone about the train's safety. The funders also got scared, and the future of the submarine trains became uncertain, just like the Hindenburg disaster ended the airship era.