If there was a genuine villain in the story it was the cowardly and arrogant Ismay, since he ordered Captain Edward Smith to set a new speed record for New York. Smith went along with it since this was going to be his last voyage before retirement and the crowning achievement of his career would have been to set a new world’s speed record. This is why they went speeding through the iceberg field, ignoring all warnings, because they also thought the ship could not sink. They expected to be able to turn as soon as they spotted an iceberg, or that it might do some minor damage, but none of them imagined that an iceberg would tear open a long gash in the hull, flooding more compartments than all the watertight doors could handle. In any case, as James Cameron pointed out, these bulkheads did not run all the way to the top of the ship, and there were some other fatal design flaws such as a long, open corridor that ran its full length and allowed the water to flow in even faster.
I have seen James Cameron in interviews and he admits that he really made the movie because he was obsessed with every detail about the Titanic, right down to the number and type of rivets that were used in its construction. He has done documentaries on the National Geographic Channel where all the leading experts explain exactly how the ship sank and where it broke in two just as it was going down. Then they spend even more time describing how it made the debris pattern on the ocean floor. Sometimes they will have Titanic documentaries on there all day, and a particularly remember one about the how a group from the company that built the ship in Belfast were chosen to sail on the first voyage. This was considered a great honor at the time, but none of them came back. After the ship struck the iceberg they all realized very quickly that it was going to sink, but they did everything they could to ensure that it stayed afloat as long as possible.