You can find it hard to believe, but until someone posts a video with scientific proof that the screen is too soft, that's where the situation lies.
Mohs picks exist for a reason, and were this widespread or even common, someone who had them or knew someone with access to a set would have posted a video by now showing the screen scratching at a level below 5.
Certainly the Android web sites and Apple rumor sites (and Forbes, who hates Apple) would love to post such a video, yet they have not.
That's not conclusive, but it's certainly telling, and would be evidence it would be hard for Apple to refute of a manufacturing issue.