> TL;DR -- all closures created within a function are retained even if only one closure is ever referenced. This is really interesting, and potentially devastating for certain coding styles. <<

This is not devastating, it is how closures and scope chain work in JavaScript. See my detailed explanation below. The crux of the matter is that the closure still references the outer function's scope chain, even after the outer function has returned. And the outer functions's scope chain is referenced by the closure until the closure is destroyed or returns.