Here is what Julian Widdows (PM) wrote for GOG about Multiplayer patch:
"We'd wanted the game to be multiplayer day one for sure and, for a while, we were developing it as a multiplayer experience. Various commercial constraints made this road difficult, however, meaning we had to cut back to just the single player experience mid-way through development.
By the time we finished the game it really was very much a single player experience, and the patch was just that - a patch to try and add multiplayer to what was now at its very core a single player game. This was a patch we had a little over three months to develop and deliver.
As I write this I come to a realisation I've never had before - the game is better left with only the thought of the patch and what it might have been like, rather than the reality of what it was like. The game, as it was released, is the game we made and, maybe putting this to bed once and for all, I think it should stay that way. The patch is the mystery box; best left unopened......"
If you want to read more check it out here.
I've nothing to add... :)