Better to Drink your Syns
I'm not sure why you think they are incompetent - its a question of supply and demand surely. If not enough people buy it then they will stop selling it and sell something else instead because they are a business and not a charity
At the end of the day 'mince' is usually a cheap way of buying meat, and obviously the lower the fat content the more expensive it becomes, putting the extra lean mince out of a lot of peoples budgets.
Logically thinking about it, the lean cuts on a cow are far greater than that of a Pig, Lamb, chicken or even turkey, which is why extra lean beef mince is widely available and the others practically non-existent.