Its not about "breaking stuff". Its about keeping the language as small as possible. Part of JS's success is being small as a language. [EDIT] For example you

Its not about "breaking stuff". Its about keeping the language as small as possible. Part of JS's success is being small as a language. [EDIT] For example you could teach functions to beginner programmers once. And could then easily introduce lambdas/callbacks/generators(And maybe block lambdas) without introducing much new syntax.