Your Stage "didn't work" because they put minimum effort into it. They only put a few (pretty boring) left and right turns and that's it. If every location had 50 different sections and more being added with DLCs every few months, the game would live for years. They could also include stage editor where people would create sections from objects already included in the game (like many old games had). But Codemasters is stuck with mentality from last century (release final game on CD and completely disregard the fact that now you can push updates over internet any moment you want, not needing to release a new CD to make changes and make money).