It's not like there some magic linguistic genie that they are going to for their analysis. A programmatic engine to determine which long sentence or use of pass

It's not like there some magic linguistic genie that they are going to for their analysis. A programmatic engine to determine which long sentence or use of passive-voice are bad or not is not trivial, if even possible with their resources. Just identifying the hopefully few uses of complicated sentences and passive-voice would allow one to quickly sort through them and make a decision on whether the usage was proper or not. They did a great job, it's a nice app.