I haven't read all the posts here.
I do get the gist, though.
When a child learns to communicate one of the things they learn to say is "why".
They want to know something. They are ignorant, in a nice way.
Until the "why" becomes tedious, usually because the listener has run out of answers or couldn't be bothered.
If you have had children, you'll know what I mean.
As an adult asking 'Why" we do so for the same reason but because we are usually asking other adults the answerer is even less clear and more impatient.
The reason for this is we adults don't think all that deep.
The answer must be coherent to the listener, relatively simple and definitely concrete.
The answer to the question "Why do we photograph?" isn't a simple question and it will never have a simple answer if we delve deep into the place were we live inside of us.
My Old Man said, once or twice, "Breath, boy. Now while you're breathing; do something"
The choice becomes ours from thereon in.
What we chose is a matter of convenience, culture, pre-requisites, beliefs, knowledge, ideas, timing, place, previous experience, capabilities, opportunity, and genetics.
It's a mixed bag with many possibilities.
DOING SOMETHING is inherently important to survival.
What we do is more a question of how we do what we do?
Secondary to that is what are the consequences?
Photography is about COMMUNICATION.
That's inherited, instinctive, and vital for our survival.
But so are a lot of other things.
We chose photography as ONE method among many to communicate.
Possibly, the question we might ask is "what does a photograph do that other means of communication are less preferable at the time?"