You are very very wrong. If you are going to hold out separate property, it MUST remain separate and never be used in the marriage. Once you use it to pay for something consumed in the marriage, it is community property.
Separate property is a very real concern where something like inheritance for children of a prior marriage, or if there is co-ownership of property with a third party who could be adversely affected if the property were to transfer to the spouse in the event of a death or divorce. Pre nuptuals and will and estate planning is the way to handle those situations. But if you are protecting separate property, it should both be known by the spouse, the rationale understood, and the principle and all income from the account must never enter the marriage spending. It's either separate, or it's not.
Certainly I am not wrong, within the laws that I understand in my own state, where I have handled divorces for 20 years. Thanks for your perspective, however.