Don't you think the fact that React.createClass() behaves differently than JS makes it less usable (i.e. more surprising) for experienced developers? The goal of React is not to fix JavaScript's warts, nor is its goal to make programming easier for non-programmers. I believe if this is the goal of your project the end result would look very different from React (probably would look more like Vue).
Where did we mention making programming easier for non-programmers? I think libraries should strive to be as usable as possible to _all_ programmers, which in this case means reducing or eliminating very common operations (such as binding callback functions). When we're talking about working on a large codebase, useless boilerplate is a legimate cost both in productivity and maintenance.
