Agreed, it's a terrible language. Among other things, it makes it way too easy to write code which many people will read as being correct, but will actually be subtly incorrect.

A few of the weakest parts:

- for (var x in y) when used for array iteration or even dict iteration; hasOwnProperty? Really?

- x[obj] = y; seriously, did i really want '[Object object]' as my key?

- the choice of function level scope over block level scope