Since this thread was about ethics, perhaps it would be interesting to talk more about that aspect.
John spoke of the two camps, one just do what you are told, irregaurdless of what is good for the tree. Camp two only does what's right for the health of the tree.
I think it's all about ethics. For example, you are asked to top a tree. Most of us would not do that. Some of us will be asked by our employer to go top a tree, and this is a tough spot for the climber.
This is why it is important to position yourself where you would not be put in this situation. If you are like me, and prefer to just climb as an employee, then find an employer that won't sell these jobs, one who will walk away from improper pruning. If you are the owner or salesman, then walk away from these customers. They will only hurt your reputation and business, in the long run.
I think removals are different than improper pruning. If a customer wants a tree removed, for whatever reason, and you can't dissuade them, go ahead and remove it. On the other hand, imporoper pruning by a proffessional sends the message that this is what proper pruning looks like, and this is the type of work your company does.
I'm not saying that I wouldn't remove one or two lower branches in a guys yard, even though it's bad for the tree. I would walk away from a job where he wants every tree in his yard raised up.