I don't think this is surprising at all. I'm pretty sure I've saved my employers similar amounts in the past, because what happens is something gets configured months or years ago, the dev leaves, everyone forgets and assumes things are how they are.

I've had to delete some really silly code that would slow things down or just force waits as a result of either dealing with legacy APIs or some other arcane reason. Not without testing or making sure it wasn't there for a reason mind you, but these inefficiencies can sometimes be hidden big problems.

The point isn't that this stuff happens. It's that a person who is trying to sell consulting services with ranty "this industry is a sham" and "it's a disgrace that it was even possible" blog posts has a website with just 5 major navigation links...and one of them is 404.