There is a dccentre in my city that is looked at by a lot of parents as a great centre (and I do think it is) but children have to be 2 to be able to go there. I have lost 2 children to it but knew that there was a chance I would. (one mom worked at the University there and the other had put her older child there for 3 years before school age) It sucked to loose them because I enjoyed both and their families very much. However, the centre offers things that I don't so I can understand why the parents choose it as well. Both parents were very honest with me and told me how hard the decision was but that they felt it would benefit their children and in the end, that is what matters to me. They both still send clients my way and that makes me feel good and we don't have any hard feelings towards each other.
Now after saying all that, if they were to have another child and ask if they could come here, I would strongly consider saying no only because I would have to fill their spot within a year or two(hard to tell though as the waiting list for that centre is long and some never get the call). If it was pretty dry though, I would take them. A year or two is still better than waiting months to fill a spot.
I am not saying this to anyone in particular but the reason I don't hold grudges against these 2 parents is because I am secure in myself and my business and know that I offer a great quality dc and excellent care for the children I have. However, all dc's are different and offer different things. Some things will appeal to parents and some won't. Just like I would pick a business that better suits me as my needs change, so will parents and I can't be mad at them for that. (but I can control how I handle them in the future)