I don't think there is anything new in that article (read it really quick), but there could be some misleading information, including diminished value which cannot be charged in many states (even if the rental agency wants it). Also utilization logs/loss of use is usually not charged in the end because in a court of law they would in most cases be denied and if the insurance company/credit company holds out long enough, they know the rental companies will give up because they know they'd be required to substantiate the loss in a court of law.
Remember, to claim damages, you have to be able to substantiate damages and loss, you cannot claim an insurance loss without cause or loss and insurance (regardless of the type) will only pay up to the damages deemed when it comes to property and reasonable is not as grey as the article makes it out to be, there are guidelines for insurance and payments, it's not just made up on the fly.