the core use case is

  var { foo } = pony

I agree this is kind of silly in isolation, but more often than not, its used like this:

  var { foo, bar, baz } = pony

which is honestly not that hard to read, and is much better than

  var foo = pony.foo;
  var bar = pony.bar;
  var baz = pony.baz;

which is very useful when you're referencing properties of pony a lot. Since you're going to see destructuring used like

  var { foo, bar, baz } = pony

typically, I think its a very nice idea to always do your variable assignments like that even when its a little obtuse. I'd rather not see multiple styles for variable assignment.

  var { foo: f } = pony

is just there as an escape hatch in case foo already exists in the namespace. It is not something you would typically do.