It takes less time, too.
I've had to use AI on some client projects (I do graphic design), and I've found it to be quite a bit more time consuming than using stock art or placeholders, because there's a level of pickiness that enters the picture when the client thinks they can have anything they can think of (they can't, but they still try).
This is an obnoxiously common practice, but this might be the most dickish version of it I've ever seen. That's so barely over the amount wtf