No and I didn't say they were.
Who says they don't ever apply? Certainly not I.
However, the wide range of valid definitions means that you cannot imply any specific flavor of atheism a priori. E.g., you cannot assume to hold me accountable for one of the more narrow definitions unless I specifically subscribe to it. For me, atheism is lack of belief in gods, period.
Hans
Sure, we can say that atheism is lack of belief in gods, period, and it is true enough no doubt. But it is a state shared by you, me, Leumas, a newborn baby, a squirrel, and a rock. Atheism is the default position of all beings that are not presented with gods, reasons to infer their existence, or assertions of their existence. And of course of all things to which the idea of belief does not apply. But in that default position it also is not a concept at all. The idea of atheism is as unknown to a baby or a squirrel as any god.
The very existence of words implies concepts to which they apply. Just to say that I do not believe in gods requires that I have an idea of what it means to believe something, and that believing is something I can do, and I have to have an idea of something that might be called a god.
If an adult human being in the world we know states that they are an atheist, then another thing has happened beyond the mere absence of belief, because the simple absence of belief of babies is so nameless and shapeless that it cannot actually be articulated at all. It is true but meaningless to say that I do not believe in things it has never occurred to me to think about at all. It is fine to say that in a perfect world that's the way it should be, and we'd all be default atheists, but it's not that way, and if it were the word "atheist" would be absent.
I contend that the definition of an atheist as simply someone who has no faith in a god, while true from one angle, is incomplete if the person uses the word "atheist," and has at least a vague idea of what he is talking about. The end result of what many of us would consider rational consideration may look the same - i.e. no gods here, never were - but as soon as you say it, you've named a flavor, whether you like it or not. Your inclusion is voluntary.
e.t.a on the question of "doing something." True, I suppose that you could say not being convinced is nothing, but I think given the pressure of society it sells character short.