Pothole damage not covered if only the tyre is damaged !! So we must rather damage the car for a valid claim ??

Driving on the R59 I tried to avoid a pothole and unfortunately my tyre got the edge of it and got a cut on the side wall. Called Discovery Insure and they said they won’t cover the damage UNLESS I had damaged the rim aswell. So basically Dicovery Insure clients must never avoid a pothole but rather hope and pray that the car gets SERIOUSLY damaged before they see it as a valid claim. So why do they repair windscreen chips then and not wait until it’s a crack and replace the entire windscreen ?