I think the main point here is that there is no hard-and-fast rule. Conditions dictate what you do. Lots of chop argues for reg in. Diving from a small boat (as pointed out earlier) requires de-kitting in the water. A lot of the research diving I've done has been from a small boat. Gear comes off before you get on the boat. And a lot of times I'm communicating with the boat tender about one thing or another as items are handed aboard. I've also done tropical guided dives where the SOP was kit in the water, hop in, kit on, dive, kit off, climb in boat.
I tend to err on the side of "whatever the DM guiding the dives says is right." They know their boat better than I do. If I'm paying them, they know the dive site and water conditions better than I do.
I do think people underestimate the risk of shore entries. I've seen more folks in trouble because they trip on a rock or fall trying to get fins on or off. The constants in all these cases are an uninflated BCD, no mask on the face, or if they do have mask on then neither snorkel or regulator in place.
I tell my OW students to inflate the BCD BEFORE walking down to the water. I let them go ankle deep so that they can rinse the "natural defogging agent" out of their mask before putting it on. Once the mask is on, they can only go deeper if they keep it on and have a snorkel (preferably) or reg in place. (Snorkel preferred to conserve air. They're diving LP 85's, and at least part of the group will be air hogs.) Fins go on in water somewhere between waste and chest deep. The reverse happens when exiting.
Even with that instruction I see (and subsequently "advise") students who decide to put fins off or on while sitting in water 1.5 to 2 feet deep. Puget Sound is placid generally, but if a ferry went buy a mile away, it's wake can sneak up on you and roll you if you're sitting down. I've seen it happen to other divers, so make sure it doesn't happen to my students.