I read "don't jump from the boat" all over the internet and official docking curricula. But I've never seen it well defined let alone practiced. What differentiates stepping 2 feet down and one fender width across from the topsides to the dock from "jumping"? Especially on boats race boats where you have to get over the lifelines too? If "stepping" ashore is defined by having one foot on the boat and one on the dock at some point that seems like "stepping" ashore would require more agility than "jumping" ashore.
The definition of "jump" that I would use is "push oneself off a surface and into the air
by using the muscles in one's legs and feet."
The definition of "step" that I would use is "to move, go, etc., by lifting the foot and setting it down again in a new position, or by using the feet alternately
in this manner: to step forward."
When you step off a boat that has lifelines, you should always step over the lifelines, first with one foot and then with the other, so that both feet are standing on the gunwale, outside the lifelines. Then step down onto the dock or finger pier, one foot at a time. When you do that, you won't trip on the lifelines, you can hold onto the lifeline or other convenient handhold with one hand for security, and you will be in complete control. If you jump onto the dock with both feet in the air, you aren't in control. You'll come down hard with all your weight, and you'll often be off balance.