Ahhhh, Nigel. Sounds lovely!
Fair enough, there's a lot of these a/c around, and a retrofit of linked controls would be huge.......
But there's really no excuse for continuing to turn them out this way apart from commonality. If Grumman can link the things on the latest Gulfstream, why can't it be done on an A380?
Really, it's doable these days, and it ought to be done.