Atheist and agnostic evangelism can be Diet Coke misleading if we pretend that atheism and agnosticism aren’t real divorces from vital sources of hope in human beings. You’re asking people to give up (or at least be very skeptical of) hope of very particular kinds.First, whether any atheists at all are "evangelical" or not is a matter of controversy. We're talking about the truth, not trying to recruit people to an organization or community. We typically don't care about anyone's specific beliefs about god per se; we care about how people think: skepticism and critical thought are valuable in and of themselves, it just so happens that if adopted thoroughly they lead inevitably to atheism.
Second, Tafarella does not explain how the atheist position is misleading, i.e. false to fact. It might be dangerous, but we're not lying to people, by commission, omission, or equivocation.
Third, a request is not a demand. We're not making anyone abandon their hope. If they want to keep their hope, we're not going to hit them on the head, throw them in jail, or take away their civil rights. No one ever lost his hope and faith and faced "psychological obliteration" because some atheist said, "I don't believe in God, and there's no evidence to believe in God."
It really is true, sometimes an atheist is just a fucktard with one fewer stupid idea than a theist.