In the linked article, Hejlsberg considers adding a new checked exception a breaking change (true), but adding a new thrown exception to not be, because "in a l

In the linked article, Hejlsberg considers adding a new checked exception a breaking change (true), but adding a new thrown exception to not be, because "in a lot of cases, people don't care." I think this is obviously open to debate. You're conflating "incorrect" with "mistake," no one is saying the C# team forgot to add checked exceptions.