Morality As a Limit
Morality as a Limit on Action
An irrational ethical system invariably clashes with one's interest. A side-effect of picking an irrational ethical system is the belief that what is moral is not necessarily good for you. Morality becomes a kind of duty. What's worse, morality becomes a limit on the actions you can take. If you didn't have a moral code, you could choose anything.
The belief that morality limits your potential is destructive. Morality is a guide to living. It allows you to act rationally by determining which values to pursue by their importance to you. If it is believed that it is a limit on your action, you will try to side-step it. You will cut corners in order to improve your life. But if morality is a proper code of action, it is your method of understanding what is in your interest. A side-step of an objective moral code is an act of harm to yourself.
A rejection of morality is a reject of an explicit code of action. It does not allow you to live without a moral code. It only allows you to avoid having a rational, non-contradictory moral code. It leaves you helpless to an unspoken, unanalyzed system of action.