Are vocal atheists stumbling blocks towards atheism?

Maybe I misunderstood this.

"The Bible tells its readers not to place stumbling blocks in the path of new believers - those who do not yet have a full understanding of their faith. I see some atheists - a minority, usually new to atheism - who want to deride all religionists for their silly beliefs. They remind me of children who try to distance themselves from their younger brother or sister, because they want to emphasize that they are all grown up - even if they are only a year or two older. With a little more growth, they come to realize that they should not be placing stumbling blocks in the path of their younger sibling."

I am not an atheist. The shortest description of my belief is often I don't believe in your God. This description works in most but not all cases.

So how does calling silly beliefs silly slow the growth of new believers? Does it also work on old believers?

I'm confused?