I'm not saying you're strictly wrong, but it's something that people have been asking about for a long time. There's still la lot of fixes etc to the main game that will be getting implemented 1st, and even in single player you can't just chose an option to enable the 3/4 player mode.
Don't get me wrong it will turn up at some point, just don't expect it in the near future.
With regards to the fixes specific to 3/4 player mode, as it's not an 'official' part of the game it's not seen as a priority yet.