We do the same. We, also, pack a dishrag. And thanks for the heads up about it being a stain removal. DH stains every trip, LOL.
I really think this is just a band aid for people to feel good about germ control. Germs are everywhere. Door knobs, handrails, the store products, serving utensils, anywhere you touch. I get the ick feeling thinking how many people have touched the cups and lids trying to pry them apart. I feel the same here on land as well. Surely, the people who are upset about a packing a personal cup have taken that into consideration. I've heard the same as a PP that stated the drink dispensers are the germ magnets. I've seen people drink a sip right there and then refill it again. So many variables to take into consideration. That one paper cup is not stopping you from coming in contact with germs. I feel that if you are that worried then just don't drink from the beverage station and your worries will be gone. With all that said, I do abide by the paper cup rule.