Not absolutely certain on this, though, but I thought it was an interesting commentary on southern French humor and sentiment.
Or, in video games / programming, a "footgun"
One thing that’s not mentioned here is that the river is really shallow (like 1 foot deep in many places). So you often have to walk the boat. And the boats have to go below bridges that are also really low, so whoever is in the boat needs to completely lie down to go under the bridges. It is somewhat scary.
In case anyone visits, this is upstream:
Looking at those pictures, I don’t see how these things are inherently unstable. I can believe they won’t feel stable when standing upright in them, and falling out of such a boat is easy, but with such a flat bottom, how can they capsize when left alone in the water? It more or less looks like an oversized stand-up paddling boat.
When a flat-bottomed ship gets out of balance, the righting moment is fairly small compared to either a deeper boat with ballast or a boat with a keel. Both of those ships are much more stable than négo chin boats or indeed standup paddle boards. Whether someone is standing on top of them to manually keep them upright is not relevant to whether the boat itself is stable or not.
My guess would be convergent evolution.
CB changes as the boat leans.
In solo canoes, lean reduces the contact area of the hull against the water and reduces drag.