My guess would be, Ford in the day was consider "THE" work truck, with its twin tuff "I" beam suspension. Tuff truck, Big motor = sales, just like the Cummins of today in the HD Dodge (RAM) trucks.
I tend to agree. They are really tough to beat. I've often wondered why they discontinued the twin I Beam front. It was simple and TOUGH. What they have now is like Tinker Toys in comparison.