While true, that's probably not the reason. U.S. legislators have never made safety regulations for industry unless it directly affected them. (Repeated info, so skip if already known). In the days of the railroad barons, Westinghouse developed a safety brake for trains, which would reduce the number of accidents. Every railroad baron was against putting this on because it would harm profits and the railroad would go bankrupt (according to them). Eventually a Congressman's family was killed in a railroad accident and legislation was pushed through. It turned out that this made the railroad barons more money than before because they could schedule more trains on a given track. Freight companies not putting on side guards is the same flawed logic. This logic is also why the U.S. is not leading the way in renewable energy and is now calling gas "freedom molecules" instead of "death molecules".