Any other game with that participation on the true multiplayer environment compared to it's sold copies would be called a fail.
I think "Don't starve" would fit good into my next example. The single player part has been sold X times. Now there is a multiplayer part that will get sold X times. Anyone who buys the muliplayer part has no advantage of the sold copies of the singleplayer part (despite more money for development).
And this is what happened here too. My gameplay experience will not be richer because anyone bought the Solo part. And if you take a look at what was promised and what we have those promises haven't been held, though the game sold so well and they got enough money to start development with kickstarter.
Certain promises haven't been held in way that you interpreted them. That's not the same thing.