It's like crossing fingers, or picking up a four leafed clover, or wishing on a star. Just hoping to take advantage of some kind of cosmic lottery system or something.
I have friends that completely not religious and they always say "I'll pray for you" if in a certain situation, and it's ignorant because you know they won't actually be doing so but it just sounds like the right thing to say sometimes and you get the point
Lack of conviction
I actually make it a point to not pray in times of trauma or fear because it'd be hypocritical of me. I also never accepted free food from religious groups when I was in college for the same reason. xD