[asveikau]

Probably a case where you don't understand what it is you broke.

Seen this too much to have any other sort of reaction. People come in without fully understanding what the existing solution does. They get overconfident that they can solve it better. They throw out the thing that is fulfilling the needs of many people. Their rewrite breaks a bunch of stuff they don't know about. But they also set the metrics for success so they've judged themselves to be successful.

If the people affected by their breakage ever manage to get back in touch, the guy that broke them is already long gone.