Yeah Kaiser, Willys, and AMCs were, but then the Wrangler came along and they thought it best to use square ones because they are more efficient. People complained but they stuck with them until 1996. Then came the Wrangler mini-van. All the yuppies wanted one because they put the round headlights on them. They didn't care that they changed the two thousand year old tried and proven leaf spring suspension, and put mini curlers under there. The problems ensued. Many issues arose from the poor design and the madness rolled over into the plastic clad JK models. Meanwhile, the military realized the problems with coil springs and commissioned Jeep to build a military version with leaf springs for more dependability and strength, in addition to the greater payload/towing capacity.
True story. The end.