I think this trend of loud hubs came about because of of the popularity of Chris King hubs, which off-roaders love because of the super fast engagement. To get that fast engagement, they have more teeth which makes more noise as the pawls click over them.
The reason Shimano hubs are quiet is because they have relatively small number of engagement points, which makes for slower engaging hub but also a lot less drag and noise.
Engagement probably doesn't matter to most road riders. It's really only a factor if you're ratcheting over technical off-road terrain and find 20 degrees of pedaling before the hub engages to be problematic. Regardless, Chris King hubs are quality stuff and many road riders use them, and may other high end hub manufacturers have similar high-engagement designs, so the noise is now associated with high-end hubs.
Those Onyx hubs look like a really cool alternative. Instant engagement and no noise, but the trade off is a bit more weight and I've heard that they can feel a bit squishy on acceleration.