There actually do exist pirate servers for many games, most notably MMOs and they have existed for a while already. They are in a grey area, if a darker shade of grey, but they work as proof-of-concept that the game's community can successfully support an exclusively-online game after it gets abandoned by the devs (Or if the users strongly disagree with the developer's policies and balancing decisions or are very dissatisfied with the network performance). Abandonware needs to be legally defined and the devs can simply be obliged to release the code for it once they decide to permanently shut down their official servers or cease all legal means of distribution and purchase channels of their software. Nobody loses, the players win.