I think this approach comes out of highly dynamic languages like python. If a typo in a variable name doesn't cause any problems until it get evaluated, then y

I think this approach comes out of highly dynamic languages like python. If a typo in a variable name doesn't cause any problems until it get evaluated, then you really need to execute every piece of the code to be sure that you don't have incredibly simple errors. If you are using languages with a even a primitive static type system, you can catch a lot of errors at compile time (or when the interprartor loads them), which provides most of the benifits of 100% coverage.