I cannot speculate why you have received those chips. But it is sad. However, after viewing many early Model S trade ins at my local service center it did become apparent to me that Xpel (or similar brand) protective coatings were the way to go, especially on a dark car.
The nosecone, front hood, front bumper and two side rearview mirrors take the most punishment and should be protected.
In second place is the L&R front fenders, L&R rear fenders and rear bumper and above the windshield at the roofline. These areas receive tire siping (siping are the fine cut channels in the outer edge of the tire) rock chips.
In third place are the 4 side doors.
Due to wind vortex, the rear hatch vertical area really does get quite dusty and filthy and due to cleaning and washing shows swirls.
To make matters somewhat more problematic, it appears that Tesla Motors uses a light grey primer coat on the S which shows very clearly any chips of the primary paint color (especially on dark colors).