You are right. They must be audited. Problem here is, for example we are a little startup company and it is impossible to afford an audition by a third party. They are too expensive. What we could do is that we open sourced our smart contract which can be viewed by anyone and anyone can check. Of course some level of knowledge about the code is needed. But someone from the forum that has this ability can do it.

Also we would love to get audited if someone can make it free of charge . We wish, it was cheaper to request audit.