Though I do feel that the whole 'child with his toys" argument could be used for pretty much any SW films, especially ANH. I mean, the DS when described to someone who isn’t a SW fan does sound like something a seven year old would come up with. Same goes for a lot of the twists, coincidences, etc. of SW. I mean, isn’t this craziness kinda why we love these films? And its not like this craziness isn’t accompanied by good storytelling, character development, etc.
I understand what you are saying, and like how people like J.J. Abrams and Rian Johnson were once those kids and got the opportunity to make a Star Wars movie. However, those aforementioned Legends stories feel more like they are from the brain of a child, rather than the heart of a child. Not to go off topic, but a perfect example of this would be Yoda having a lightsaber. A decision that the creator himself even made that contradicts everything of what made Yoda the incredible character he has been for almost forty years.