Angry atheism (which isn’t always meaningfully radical) has just as murderous a history as angry religion in the last century or two.
Why any atheists would seek to impress by emulating that, even if only in tone, is no more obvious than why any religious or political people would. And yet, some of all of these do, and seem to get some applauding audiences.
Wherever it turns up, it’s dangerous, because it’s equally useful to those who are looking for someone to use.