iPhone 11 being scratched even when inside bomb proof case?

Yes, well it's either 'one of the world's leading motorcycle accessory companies', which sounds really impressive, I'm sure, or one of the world's leading mobile device manufacturers, which sounds, I'll argue, at least as impressive, ironical or not.

Feel as you wish, but I'm afraid that the variable here is the "protective" case.

It's not your case.

It's not how you use the phone.

The screen is different, somehow. This is why you can't just replace it anywhere

and Apple insists on repairing.

Is it just 'softer'glass, less likely to crack, or something else?

The picture of the back looks like it’s got oils on it and not wiped well so the oils smeared versus cleaning. Or...it was wiped with a fabric that it shouldn’t have been. Not scratches from a poor glass. Not sure about your case (not familiar with it) but what you’re showing looks like handling versus defective. Don’t see that kind of damage to my son Red iPhone 11 and he has it in a Otterbox that is open in the front and allows dust particles to get between the case and phone. I remove it once a week to thoroughly clean and wipe with a micro fiber cloth...none of the extensive swirls or marks yours show and no scratches from the dust/dirt particles. No issues on either 11 pro Max in the house also. Otterbox folio cases for those. All 3 use a cheap screen protector (not a glass one). Actually never had a scratch or damage to my iPhones in the past either. Similar or same cases on each model.

Seems like you have questions for the Case Maker...

Well I've never used a case at all and I've never seen anything like that damage on any of my phones. The only source of the damage - per your report - is the case.