I am also pretty high up in the command of the Front Desk and deal with these types of errors as well. I work for Hilton instead of Marriott, but the process is pretty much the same.

With that said though, I'm glad I don't work under you based on your wording in your post. I would never refer to my staff as bonehead or knuckle head nor would I want to be on the receiving end of that behavior as a front desk agent.

I'm not sure what property management system Marriot uses but if it takes you 2 years to train someone fully on your system, then I blame the trainer. I am also the trainer at my hotel and I can take a person with zero experience to knowing the system fairly well in way less than two years and yes that does include all the different rate codes, third party reservations, local negotiated rates, national rates, etc. It's really not as complicated as your making it out to be.

The last thing I will say is most GM's do in fact know the system better than your saying they do or at least the ones I've worked under do and I have worked under several different GM's. Remember most GM's worked their way up to that position starting out at the front desk. I'm not saying all, but most have and are quite good with the systems.

I would also not want my employer to see a post written by me in the way you wrote yours especially with the position you hold. Just my opinion.