dicepro: I've thought a bit more about your comment about "...playing backgammon many times with doubling cube used right away...", which you described as being abusive.  Maybe I need to know more precisely what you mean by "right away".  If that means "as soon as legally possible", I don't have any strong moral feelings about such players' actions, but I'm absolutely convinced they're committing strategic errors (at most match scores, anyway), by voluntarily giving control of the cube to you without justification by the current game position and match score.  Possession of the cube has been described as a tool or a weapon--it's undeniably a thing of value at most match scores.  Generally speaking, I'd welcome the opportunity to play someone who wanted every game to be played at double the initial stakes, but with me having initial possession of the cube!  In such a case, I'd have to say "Please, let's sit and play--and don't forget to bring your wallet!!"

But if "right away" instead means "very early in the game"...well, I'm not sure what's abusive about that, either.  It might feel like one is being pressured earlier than expected, and such decision-making can be quite uncomfortable psychologically, at a variety of match scores.  Here, too, the opponent is offering more than a doubling of the stake--they are offering you sole possession of the cube, and the exclusive right to be the "abuser", one might say.