I don't know how morals fits in this discussion. I would say scratch building exhibits a superior skillset. That, I would think, is obvious. I have scratch built complete and partial models. I also build OOB once in a while, too. A scratch builder is more skilled than a model builder who does not scratch build. Scratch building is a goal for many and a worthy one.
One day when I was much younger, I was thinking about what a hot shot model builder I was and it occured to me that someone else made up all of those parts I was putting together. If I was such a hot shot, why don't I make the parts, too!