The word "failure" was never used. But, they are technically correct. The language is defined as by CPython: it is the standard!!! None of the others fully mee

The word "failure" was never used. But, they are technically correct. The language is defined as by CPython: it is the standard!!! None of the others fully meet that standard, which includes quirks! It's knows trade offs with them! They are, literally, attempts to adhere to that standard.