okay i looked it up and apparently atheism can mean a lot of different things. it can mean you either believe there is no god, or that you are basically agnostic, or something in between. (at least that’s what i got from the wikipedia page.) but anyways, the whole “burden of proof” argument does not apply to all forms of atheism, as certain kinds of atheism involve an active belief that no god exists. however, the “burden of proof” argument does apply to all forms agnosticism. so it is still a better argument for agnosticism than it is for atheism.