and have treated all of my non-trailerable boats that way. The thought of even a gentle grinding of the bow on sand in a deliberate beaching makes me think "there goes the bottom paint".

OTOH, there have been several times over the years when I wandered out of a shifting river channel and triggered the centerboard to release and pop up. I'd rather lose a little paint (or worse if I strike rock) from the tip of the CB than from the main hull.

And there are times when anchoring or docking in shoal water is an advantage, and that might mean risking gentle contact with the mud or sand at extreme low tide. I generally chose to skip taking those risks, mainly because one never knows what's on the bottom (especially here in New England where the visibility is poor) and I don't want to risk "point contact" with rock or metal debris. I calculate the situations pretty carefully to avoid contact. But there's always the possibility of hitting an abandoned mooring shank or wreck. (I hit a mooring shank with my outboard prop in a 13' Boston Whaler a few years ago, it was just under the water.)