A funny thing that happened today at my catholic school-in theology we were talking about how you're automatically excommunicated from the church for things like heresy and abortion and shit. But the funny thing was rejecting the church was a reason for being excommunicated?? My friend said it's like being excluded from a club you don't want to join. Like "oh no I left the church because I don't agree with it? And theyre kicking me out? GOOD. I don't want you anyway."
I agree for a strong atheist it can be kind of silly to be told you’re not welcome into a community you don’t agree with. The irony is real.
But, if someone who “lost their faith” wanted to return they would not be welcomed back.
Weak atheists or even strong atheists who were once strong believers (even strong atheists who simply found some sort of comfort within the church at some time or another- or perhaps their family has deep ties to the church) who is told they are never welcome back may see it as a bit more than silly. Sometimes it is hard to let go of, or have removed, a large part of your life/childhood.
And for those who feel they were wrong about atheism and want to return to their community it can be devastating.
Although, if my information doesn’t fail, most modern churches offer forgiveness if one were to “Return to their faith”.