You're right. If the crash was head-on, it would have awakened everyone, and some people may have been injured or killed, but the.number of casualties would undoubtedly be less than 1,500. Also, the ship would have stayed afloat because the crash would only damage one watertight compartment. They could have just put the ship in reverse, gone around the iceberg and continued to New York.
But then people would believe that it was possible to make unsinkable ships. Maritime laws would be rewritten to allow for fewer safety measures or eliminated completely. For example, the Titanic would be followed by a even bigger cruise ship with no lifeboats, and that ship might sink with everyone on board.
So in a way, the sinking of the Titanic saved lives by leading to stricter maritime laws and preventing future tragedies with more deaths.