Sometimes reading this forum I feel sorry for the decison makers at Marriott -

I agree with your point about "green" - but I do not drink the {gift bottles} in the room; but carry them with me through the day.

I think you offered your own solution - If you (or anyone) does not want the bottles, then ask to trade for something else. Were enough people to do that, I am certain Marriott would begin to offer other options.