Listen servers are an ancient way of connecting players together (the early dark ages of gaming, 1990) that was brought back for consoles because dedicated servers weren't practical for that platform.
Dedicated servers were brought in as an improvement on listen servers with Quake 1 because of all the major latency, insufficient upstream, reliability and host advantage problems (problems in every single console multiplayer game). They nowadays also allow the game's community to live on many years after the game's release (Quakeworld for instance) and players to create custom content.
If ID Software had the foresight more than 10 years ago to realize dedicated servers were THE way to go, how the hell does one of today's most prominent FPS developers make such a backwards mistake, literally forcing us back into the dark ages of gaming.
