Unlike the small-a de facto atheist who merely doesn't happen to believe that gods exist, the self-styled atheist is much more accurately described as an anti-religionist in general and anti-Christian in particular. And again, only a socially autistic Capital-A atheist would find it hard to understand why religious people might be hostile towards anti-religious people who actively want to eliminate their holidays, their jobs, and in some cases, even their lives.

Moreover, no one likes a liar and most atheists lie about the source of their atheism. ...

First, while most atheists claim that they gave religion a sincere try, it is patently obvious when they haven't because one can reliably expose an atheist's ignorance of even the most basic Christian doctrine, let alone more obscure religious doctrines, with only two or three simple questions. Second, the age at which most people become atheists indicates that it is almost never an intellectual decision, but an emotional one. (This is why most self-identified atheists are angry, bitter, and immature. The anger, bitterness, and immaturity are usually the cause of the atheism, they are not, as many Christians erroneously suppose, the effects.) ...