Maybe they were still there because Biden on July 8 said: "the likelihood there’s going to be the Taliban overrunning everything and owning the whole country is highly unlikely". I suggest you read the attached before responding, particularly the Q&A starting "Is the Taliban takeover of Afghanistan now inevitable".
East Room 2:09 P.M. EDTTHE PRESIDENT: Good afternoon. Earlier today, I was briefed by our senior military and national security leaders on the status
www.whitehouse.gov
Biden completely downplayed the risks (ignoring the statements and advice of US Intelligence). Now it has exploded in his face, he claims that chaos was inevitable and was built into his calculus. Breathtaking ineptitude garnished with a labyrinth of mis-truths.
In the face of this, your statement that "Americans still in Afghanistan at this point SHOULD be on their own" is utterly staggering.