Notes:
Motivation and support are two key determinators of the success of a project. (Skill is another.)
This principle assumes that there are motivated individuals to hand (or that you have the means to motivate them) and that it is clear what support they need and how to provide it.
There are a lot of developers in the industry that are unmotivated, and a lot of organisations that are not supportive environments. Changing these factors is not trivial (and would be the subject of a different talk).