I didn't see a consensus, and maybe that's the valuable thing to get out of the discussion.
It suggests another question - why should I, who has no skin in the game, care if a game "succeeds"? I can see why, say, Morrus cares if a game or product meets his business goals, and is thereby a success, to him. But, what is my reason, as a player/consumer, for wanting to put that label on a game? What value or utility do I get from categorizing games as successful or unsuccessful?
I am not sure I get much. I don't care if it is "successful". I care about more specific things - like whether it still in print/available, if it popular enough that finding players will be easy, and if there a lot of content I want supporting the core rules, and so on. Even if I label a game "successful" I will still have to answer those practical questions separately.