You don't happen to work for BT by any chance do you.........?Depends on the need for someone to get promoted.
You don't get picked up as a high flyer for just doing a good job. You have to be seen to have made a 'difference'
So, you change something that has worked for decades, and trumpet it as the most innovative thing since sliced bread. Then you get promoted, and are safely away before the consequences if the change appear.
A few years later, someone who needs a promotion reinvents the thing that was changed...
Rinse and repeat.