I don't think it's that extreme. Lets do away with any sentimentality; at the end of the day it's only a fish, a creature we exploit (basically a commodity), so not really any different to a farm animal.
As such should be culled out once (if) it becomes substandard.
It needs noting; you say you don't fish commercial waters but going by the pics taken of your recent trip to France, the fishery looks very much like a commercial water?
But then if every fish with mouth damage was culled, we'd lose (at a guess) over 50% of the countries carp.
When I say commercial, I mean lakes built for match fishing, full of tens of thousands of small carp, where you can go catch 100's of them a day and squash them all in a keepnet. Basically, where fish welfare isn't of primary concern. Hence the poor state of the fish.
The lake I fished isn't commercial at all. It's never been advertised and fish welfare is of utmost concern. 2 people were told to pack up and leave after the first night (they were on a week session) after sacking a mid 30 at night till the morning.
---------- Post added at 00:12 ---------- Previous post was at 00:01 ----------
I think bad mouth damage has something to do with 1) use of heavy leads 2) use of heavy lines and over-powerful rods 3) poor unhooking skills
Some also argue that barbless hooks are worse.
I would like to know is the damage caused when the fish are still young and lips/mouth soft, or later when you would think they should be more resilient.
Whatever the cause it would be enough to put me off fishing an affected water and is one of the main reasons i have little interest in carp fishing. I have no intention to catch a known fish, particularly if it has been damaged by previous captures. Rather catch a smaller pristine or uncaught fish every time (even if it is an easier proposition).
One of my clubs waters was built 15 years ago and stocked at the same time with fish from farms. So all uncaught fish.
There is a max hook size rule of 8, only running leads and no braided hook links.
Yet pretty much every carp has mouth damage.
I'm on the committee and we have the place netted every few years to sort out the stock, keep tabs etc and the guys who net it, are adamant that the most common cause of mouth damage is tiny hooks and fine lines. Tiny hooks rip out and fine lines act like cheese wire and saw through the corners of the mouth.
The barbless hook thing...I've heard that too but have never been able to work out why. I thought people insist on using barbed to stop the hook pulling in a fight, which could then end up in the fishes eye, flank or any other part of it.