Its a political Gordian Knot. Real estate is always nice to have, but if you are going to spend crazy money enforcing and bribing and pleading with Afghans to maintain some sort of law and order (no, its not just guarding the mines, that's pointless without also guarding all the long and remote roads that would lead to them) so that mining business can exploit it in peace.... not necessarily worth it. Worse yet, it could be a Chinese business in the end, its not like they lack money or willingness to bribe third world officials.
For cultural and political reasons USA can't just go "Afghanistan is our resource colony now, here's their military governor, whoever doesn't like it can go and perform some physiologically impossible act of self-abuse".
If China wants it, they can go in and do exactly that, they can even put millions of unruly Afghans in concentration camps and turn it into a Xinjiang on steroids, but at least let them pay all the related costs in bribes, new infrastructure, blood, and PR, don't pay a big chunk of that for them, that's insane.
Pakistan is the surprisingly unspoken about elephant in the room here.
The head of the Afghan army tells BBC HARDtalk fighting in Afghanistan could be stopped "in weeks" if Pakistan told the Taliban to end the insurgency.
www.bbc.com
Sometimes the truth slips out, and it is still true. Taliban may control Afghanistan like they used to, but Pakistan always had a certain, hard to qualify, but meaningful degree of control over Taliban.
Let's see what he has.
I would have expected better than sunk cost fallacy argument from a professional...
Who's "we"? Sure, it would be in the interest of Afghan government, but how is it in the interest of American government?