So basically the whole non-Hindu world should also stop eating beef in order to not insult Hinduism?
No one is really forcing them, if I remember well, there is porn about mohammad made few years ago in a European country, who stopped them? No one.
Because it's bad manner. Nobody's stopping you, but the majority of society will look down on you if not for violating their basic beliefs, then for being extremely bad mannered. You may not care if someone else steps on your beliefs, but most arrogant atheists fail to be able to view it in their shoes completely and completely fail to analyze it properly. Some people are sensitive to this as it offends them the same way as if you pick on an Arab because he's Arab (you pretty much step all over his identity and spit on him while he's on the ground)...it's just plain wrong.
If it's one thing to say to all Atheists, you guys seriously need to manner up.