The best games are also the most addictive. At least many single player titles end sooner or later but online ones are endless.
Pft says who? Few of my favorite games can be described as addictive. You can't simultaneously make the argument that "addictiveness" in the sense you're using it is bad, and then quickly switch word senses to claim its a requirement for very good games.
By "bad" I mean the impact of this game design on players' lives – the game is "too fun" for some of them.
I think there are a lot of players that see the Skinner Box-like mechanics popping up in mainstream works, and are increasingly turned off by it too.