The article doesn’t say atheism implies a particular worldview. The point is that atheists tend to reject theism by appealing to reason and by concluding that theism is irrational.
When I talk about secularism here, I’m talking about whatever nontheistic worldview the atheist subscribes to, and I briefly consider the nihilistic option of not having any worldview. I’m not presupposing any particular secular worldview in the article.
And I don’t “arbitrarily” extend the definition of “religion.” The distinction between religion and theism is based on sociology and existentialism, not an arbitrary whim, as I explain in the article.
I don’t get your third objection.
Theistic worldviews have certainly proven to be dogmatic, but whereas scientific theories are held tentatively, that doesn’t mean philosophical naturalism, materialism, empiricism, skepticism, transhumanism, neoliberalism, or whatever secular worldview the atheist has is held non-dogmatically. We’re all pretty dogmatic about our core beliefs and values.
My objections against atheism don’t reject reason or rationality. My point is that the use of reason depends ultimately on nonrational values and convictions, not that we should never try to be rational. I say that science and philosophy are useful for certain purposes. So I don’t see a self-contradiction in using reason to point out that reason has limitations. A self-contradiction would be to use reason to say that we can never be reasonable.
By the way, my three objections aren’t meant to entail that we should reject atheism. I’m an atheist. But some kinds of atheism are stronger than others.