I don't know, from my point of view having both syntaxes is clearly more to think about, and all you get from the shorter one is typing a few fewer keystrokes.

Philosophically, I feel a little ambivalent about the briefer syntax because it mixes two sorts of denotations. Variables refer to scoped objects for which, from the point of view of what the program means, vanish (in compiled languages they literally can totally vanish - variable references are just resolved into the appropriate reference to memory). The keys of a hash table are totally different sorts of things and persist at runtime. I'd prefer that these two very distinct conceptual spaces remain separate, even if in a certain sense they overlap in a specific case.

Doesn't really matter, though.