It has to do with the fact that he gave them the work of their lifetimes.
I think there are a huge amount of people looking to apply the sum of their knowledge, skills, and worldviews into a project that they can be proud of. When you think about Disneyland being an empty piece of land on the outskirts in agriculture area and think about all the artistry, architecture, construction, and planning challenges of making the most magical place on earth, Walt gave many people the work their were longing for and never knew it.
While Walt loved creating the whole idea, he didn’t create the individual components. Walt was the pitchman, the fundraiser, the visionary. No doubt, at times it would have been much more fun to be the animator, the architect, the animatronics specialist, but someone needed to raise money for the vision to come together and create the opportunity for everyone to do the work they are proud of.
Elon Musk is doing the same thing with electric vehicles, internet, and space travel. Some people don’t like him because he seems to take too much technical credit, when in fact there is no need to do so. The work he does in connecting, raising funds, pitching the ideas is important. It seems to me that Walt is favored more than Elon because he was a bit more forthcoming about the others doing the work to make Disney what it is.
There is much more room for connectors. For the people taking responsibility in order to give other the work of their lifetime. In fact, if you think of some massively technologically advanced society a few hundred years in the future when robots can do most of the labor, it may be the only work left.
Regardless of the world and it’s current economic position, there is always room for someone to stand up and say “I have an idea.” Then connect the resources needed to make it happen. That last part is the difficult part.