And they’re right to do so.
If you download the original 2001 game, you are playing with the database from 2001. While nostalgic, you cannot play with modern teams or players.
Once you have the game running, part of the fun is exploiting the famous "cheat" tactics and wonderkids that only work in this specific game engine.
If you download the ISO (the raw game file) rather than the pre-installed version, the installation process is tricky. Here is the step-by-step: