As has been mentioned earlier, we book the ADRs as a service to our clients. We don't charge extra for this service, it is complementary to our clients. It is our company policy that we book only for the clients that we have booked.
That being said, if a client asked me if I could add a couple people to their reservation because they were meeting family in the area, I likely would do it but I'm not going to do it if it makes me have to do more work than I already would be doing for the client (ie calling group dining instead of booking online).
There are a number of complementary things that we do for our clients. I have to agree that it's not right for anyone to expect me to extend those services to someone who is not my client. If I choose to do so, that's my business, but it is wrong to expect me to do so for those who are not my clients. And it certainly doesn't give someone the right to be mad at me because I am following company policy.