Atheism is just a lack of theism, theism is a belief in God(s) ergo atheism is a lack of belief in God(s). A failure of proof disproof, aka the theist does not provide a convincing argument, is ground enough for holding a soft view. Much as the Null Hypothesis in science.
If atheism is "just a lack of theism" then as aforementioned, my kitchen appliances are also atheistic as they lack belief in theism. For me to lack X, I must be in a state without X. Agnostics would also be atheist under this definition. Amoebas would be, too. This is a basic reductio against dictionary atheism.
Atheism in the actual academic literature (rather than online counterapologetics where everyone is apparently a philosopher) is treated as a positive assertion.
Atheism is a philosophical position on the existence of deities. We assign philosophical positions to entities that have the ability to construct beliefs. Spoons and rocks can't form beliefs. Calling a rock an atheist makes no more sense than calling a rock a compatibilist. However, on lacktheism a rock is an atheist as it "lacks belief" in God.