What is the weak link for Chevy max tow ratings?

Not to dispute the last two responses to my comment but the question was "For a Silverado 3500,they are about 23,000. That is 4.5 tons less than a Ford and 4 tons less than a Ram. What is causing such a low rating?"

I just thought that the article I quoted might help answer the op's question. Maybe it doesn't, maybe GM will give us the true answer but I am not going to hold my breath on that one.