I don't recall Doom being particularly well-known for its multiplayer. The vast majority of work done by fans and developers alike for Doom 1 through 3 have been focused on singleplayer levels. Nobody asked for a strong multiplayer component for Doom 4.
I think as much as anything it is that id haven't really done anything big MP wise lately for any of their FPS IP so people hoping Doom would be it.
 
	 
  
 
		 
 
		 
  
 
		
 
 
		

 
 
		
 
 
		 
 
		 
 
		 .....man this must be boring.
.....man this must be boring.