I agree with you wholeheartedly. In my own experience, if you expect to be paid waiting time at all you must have listed in/out times and a signature from the shipper/receiver acknowledging that they are aware of the amount of time you were there. And, in light of that, any time you are paid for is explicitly on duty time and must be recorded as such.
The DOT would have a field day with the idiot who logged off duty to preserve their hours with an express acknowledgement that they were at a customer during that time. I agree that there's room for abuse, but the E-logs can't be lied to like the paper logs, so it becomes the choice of the driver. Forfeit pay and preserve hours? Forfeit hours and get paid? Or lie and hope you don't get caught? The customer can't tell you what to do, and neither can the carrier. Strictly speaking, the DOT says you must be on duty and nobody can argue that because you are attending to a customer.
You can lead a horse to water, but you can't make it drink. Some drivers will steal every minute of every day that they can because they don't have a family, or even a home, to go back to. They risk serious fines to make a few extra dollars. And they would do it one way or another. Should we really worry about the handful of cheaters still left out there so much that we would forfeit something that has the potential to be of great benefit to drivers who do play by the rules?
I will tell you this much, my friend. I've only worked three 16 hour shifts in my life. One was at FedEx (I logged my time waiting in Toledo off duty, I wasn't paid for it anyway so it didn't matter) the Friday night of the weekend my dad got married to his current wife. I was expected to be at the wedding, but he needed the night off to prepare, so I deliberately ensured my 16 hour clock to allow me to complete the run by myself and thus be present at the wedding. I was utterly exhausted, but I was present and my sacrifice was noted.
The other two times were because of weather conditions in British Columbia causing accidents that closed the roads. And frankly, anyone who would routinely subject themselves to that many hours in a day probably deserves the burnout they'll inevitably complain about. Especially if they aren't being paid for all of it.
Long-winded response, perhaps, but I just wanted to spotlight what it's like and the reasons someone would really have to have in order to go to that extreme. It's not something you'd want to do for free every day, and I genuinely don't believe that anyone would want to experience a day that long more than a handful of times unless they really were napping the whole three hours.