From the conversations I have had so far, I see little to indicate that Goldman Sachs sees Bitcoin as a threat of any kind. There's nothing to prevent Goldman from speculating in Bitcoin and they can even accept it as payment if it is successful enough. If they can make money with it, obviously they will.

That said, Goldman is not in the business of making "early stage" bets. They usually wait until something is reasonably mature before moving in. Since I'm sure they have analysts working on digital currency happenings, Ethereum could very well be a good entry point for them into the market.

Fundamentally the "door is always open" with the current cryptocurrency model. When you distribute everything, you allow whoever wants to to play in the same sandbox you are playing in.

If this bothers you, you might want to seek out another model.