Yes, but they did ask your son. Perhaps they used different criteria - which of course is fine, because there is no absolutely correct criteria.
It is good to see that he will be going. I'm sure he will gain something from the day, even if it isn't the same as others gain - often the way that different people gain different things from events.
During this thread, people have pointed out that your early suggestion that your son didn't need the course and others did and that perhaps he shouldn't go could be seen an patronising - you didn't like those comments.
Many many people said you should send him and pointed out all the positives for any individual child of such a visit, as well as for him specifically because of the kind of school he is at - and you didn't like it.
Frequently you have quoted people on this thread and then disagreed with them - perhaps only once or twice seeming to like something said.
You have accused people of rudeness, when people's comments about yourself or your son have been intended to be helpful and point out to you how saying your privileged son will benefit less than others from such a course, will come across to others.
Quite simply it seems to me that you have no appreciation of the views of others or ability to take on board what people say, even when voiced by numerous people and supported with good evidence. I find it bizarre. I find it bizarre that you would come on here to ask a question but be totally unprepared to hear any of the answers given or to even consider that your initial ideas could be amended in any way. The fact that you have been so dismissive of the vast, vast majority of posters and their views on here, is why a couple of people have said they don't really are what you do - it is a response to your refusal to even consider the well thought out ideas of others.
At the end of the day, we all engage in these threads, not because we really care that much about your DS, but because we enjoy a discussion - if the discussion is able to help someone make an informed choice, then all to the good. When the discussion becomes lengthy and the OP refuses to hear what is put forward over and over again, that is when people finally respond with 'we don't care' - it is a response of frustration because people have actually put in the time to answer your question and feel they deserve to be heard, especially when 99% of people are saying the same thing.
What did you want when you started this thread - that everyone would simply agree with you? It really seems you didn't want to hear the other side, because you have never acknowledged any validity in it at all.
I hope your boy does go on the day put and get something useful from it. I hope you are able to make clear to him that it can be useful to him too and that you aren't pushing a message to him that he is different to the others, because that will never go down well if he then puts it across to his peers in the superior way you sound as if you put yourself across to the school and other parents. Empathy and awareness of others is a great thing.