Deathbed unconversions

In "Laughing at the angel of death" I wrote about the stupid slander levelled at so many rationalists, that when in fear of death we suddenly believe in the afterlife and any god that promises salvation. This nonsensical statement has been made about many famously nonreligious people, notably Charles Darwin.

It turns out that this offensive lie isn't limited to the West. Basava Premanand, published of Indian Skeptic, is dying of cancer. God-peddlers there have been circulating the atrocious falsehood that on his deathbed, he has suddenly become religious, forcing a man too weak to sign his name to take the effort to issue a declaration that:

I do not believe in any supernatural power. All the powers that we encounter are in the realm of nature and nothing exists beyond that.

I do not believe in the existence of the soul or rebirth.

I have not turned to any religion, god, or any sort of spiritual pursuits.

It's funny, but I don't recall rationalists claiming that on his deathbed, Pope John Paul II suddenly became an atheist. Why do the religious feel this strange need to lie about unbelievers?