[JBrunner]

This also makes a lot of sense...

Without trusting the exposure, you can check all kinds of things. The lights are in the right place, no unfortunate shadows... Have a chance to catch things that you can see in the photograph that shouldn't be there, like backdrops in the wrong place. Just "see" if the picture has a chance to work at all.

Yes, exactly right.

I think what is missing here is a photographers interpretation of a particular emulsion. I don't expose any two emulsions the same way, even if they have the same box speed. If you are really going for it, you need to know your film, and accurately predict its behavior, so above all I need an impartial tool. A histogram or image from a chip with a different response than the emulsion isn't impartial, in fact it's likely to be wrong. Luckily, the film can forgive this, but you will never get back what isn't there, which is the likely case, to my thinking.