That's the thing - I genuinely don't understand the user or usage Venn diagram : when and who will 1. Have an expensive ipad with them and require a good big camera, but 2. Not have an equivalently competent phone with them?

Don't get me wrong, I understand it happens - back when I did wedding photography, one of my massive pet peeves were the uncles and grandparents who stepped into the aisle with their massive tablets just as bride is starting her walk... But I do not understand it at all :-/.

I'd absolutely happily completely kill the rear facing tablet camera. I've had at least a dozen android and ipad tablets and I genuinely don't think I took a single photo with them - it'd feel weird and awkward and so ostentious.

(As always as a consumer, clearly I'm in minority here :-})

When I use the rear camera, it's part of a feature of some other app that clearly makes sense to use as a tablet. You're bogged down as it being used as a primary camera as a photographer. There are other needs for cameras other than portraits. Using the rear camera in an AR mode is quite handy in apps.