Disliking a religion is not Racist

Why is it taboo to say I don't like a certain religion? There are billions of religions out there and there are even some that suggest for example that we should perform sacrifices and even cannibalism. We have no problem condemning these types of religions when its smaller known or more foreign to us but when it becomes more popular suddenly "hey don't tell me I can't eat people! I have the freedom to believe and practice whatever I want!"