So I'm browsing around one of the many sitewebs on the internets and I read a touching story about a girl. Someone says "bless her" and I not-so-kindly inform them to keep their bullshit out of this. Now, of course, I get bitched at. It may sound reasonable to you, but if it had been me saying "oh isn't she cute and btw god doesn't exist" I would have been told that my comment was inappropriate.
Why are those different? Yes, I know that "bless you" is meant as a kind gesture but it's also a religious one in nature/origin. I don't see why you need to push your cultist bullshit when wishing someone well. Just keep it to yourself.
I don't say "religion is bullshit" when someone sneezes so I'd appreciate the same kind of courtesy from religious people.