It's a simple corporate decision, based on their current handful of products. The J-series is only Honda's first and only 60 degree V6. It's a relatively old design, and minus the tinkering of heads and displacements, it hasnt changed. A good engine, but when it was designed, timing belts were the Japanese standard. Honda is not going to dump money into retrofitting the J block with a consumer-frienly chain because it only benefits the end consumer, and takes money away from their dealers. We'll just have to wait for Hondas next 60 degree V6 for a chain. Also today's chains are just as quiet, if not quieter, than timing belts. The belts are definately not noise-free, they often make whining and resonance noises, and they flap when tensioners get old. Just wait for Honda to finally update/replace the J, and you'll be guaranteed a chain.