If it wasn't security they'd just pick a different pretext. "Oh you violated some comma in the 1k page eula, we gotta ban you now, can't set a precedent of allowing violations ya know" or some crap like that.
Security, safety, liability, risk, equity, inclusion, god, any word or concept that it is not socially unacceptable to consider anything other than an unalloyed good WILL be used in this way.
Note that the former employee of her company was still left permabanned even after producing the ID, per the post.
So I can totally understand why she wouldn't play those games!
To be frank, it would seem that producing an ID in such a situation, is pointless from the user's POV. It seems like it's simply abused by the vendor to institute and enforce a permanent ban.