I agree that dialog is always good. But the truth is if some conductors are repeatedly running awful trains and people stop riding them then they can't run trains anymore since no riders will ride them, thus leaving the honest condutors and trains.
Give appropriate feedback. Also pm the conductor if it arrives in bad condition to see if they will do anything for you. Everyone(Riders and Conductors) are taking a risk when riding a train. That is a fact. A conductor could send out a great train and yet a rider could get it and find there is nothing they need but the next rider might take a ton. Does that mean the train was bad? No. Riders need to be just as honest as conductors. I have some great riders that ride my trains consistantly. Sometimes they will get a train that has nothing in it they need. Yet they will still leave positive feedback and send a boarding pass even though there was nothing they needed. Why? Because there was a good selection, it arrived in good time, gave clear instructions and they had a seat. I can't predict as a conductor what all my riders need. That is impossible. Now if the conductor sends out a train that has all crap. First contact the conductor to see if it was the conductors fault. When I have had a rider raid my train and the next rider contacts me, in most cases I will ask them to restock the train for the rest of the riders and they get some type of compinsation in return. If it was the conductor sending out a crappy train and they refuse to work with you and such then leave appropriate feedback and then write their name down as a Do Not Ride list.
It is a two way street. Conductors taking most of the risk though. I don't know any conductors that run trains just so others can have a chance at coupons they don't normally get or that they want multiples of. I run trains so that I can get some coupons I want and also so I can see coupons from all around the country and get some I might not normally have access to.