I've clicked on a number of these tables, and the issue that I run into is that each developer is using a different (if slightly overlapping) set of tools in their environments. Is Node required? Webpack? Gulp? RequireJS? etc.
Because most of these assume that the developer has the same tools installed that they use every day, it's an uphill climb to determine tool and library dependencies.
Ideally, the simplest example for each would not require any dependencies other than React and a clearly state JSX -> Javascript package (Ok, and also maybe JQuery). Other than that, they should be able to easily run behind any Web server.