They are spirits that were commonly worshipped in ancient times. Cultures that worship them are no more or less sane than anyone else. They have had different customs and opinions on morality, but that is a different matter entirely.
It sounds to me like you've read or heard to much about H.P Lovecraft's Cthulho (the miss spelling is intentional). As you also state that "they are more demonic", which Lovecraft's Elder Gods truly are. And they are also purely fictional.