That’s because there are different people with different opinions.
Some really are ridiculing believers for believing in fairy tales. I for one, do not care what others believe, so long as they do not impose their beliefs on others.
Others simply ridicule the act of using their fairy tales to tell others how to live their lives.
And for some people it’s less about ridiculing anyone at all and more about trying to somehow convey the idea that, silly or not, that argument isn’t going to work here.
I never ridicule people for their beliefs. However, saying “I know there’s a God and you will stand before him (always him) in judgment after you die” is ridiculous. You might belief it, but you certainly do not know it.
If I don’t believe in god, I can’t ridicule him. I can’t ridicule someone that I believe doesn’t exist.
If I were to use Flying Spaghetti Monster or similar expressions, I wouldn’t be ridiculing god. I would be pointing out the absurdity of the idea of a god, particularly the Christian idea of god.
I agree that the “because (I believe) God said no abortions” or “God will punish you if you have an abortion” are ineffective and counter-productive arguments, not only when used against those who don’t believe in God but also for many who do, as quite a few Christians are pro-choice. I also strongly object to those who confront and verbally attack women going into clinics where abortions are performed, especially those (the majority, I think) who consider themselves Christians.
Similarly, ridiculing someone’s belief in God is also ineffective and likely to be counter-productive.