I like a revolver with a shrouded hammer because you can shoot it right through the material of a pocket without removing it and you don’t have to worry about a slide or hammer getting caught in the clothing.
Aha! A person that values the meaning of words. Of course "hammerless" revolvers have hammers, they are just shrouded. But the saying, as so many in the gun world, has gained traction and will never be rooted out.
You can blame Smith & Wesson with their "Safety Hammerless". It probably sounded snappier than "Safety Shrouded Hammer".