My guess is that the majority of the thousands & millions of Marriott rooms that get booked are done so at rack rates, publicly available rates & corp rates that people are entitled to, rather than the majority of them being booked at rates people aren't entitled to. My guess is that the % of rooms being booked at rates people aren't entitled to is relatively small.
I'm glad that the code list is above because there are publicly available rates in the list that I didn't know about that have helped me save some $$ (especially at LHR Renaissance). And while they are publicly available it's not like Marriott's promoted them in ways that the average Joe would know about them.
Cheers.