Agree, bad move by Trump. McCain was shot down and seriously injured pressing an attack on the enemy. Not his fault.
That said, McCain, the son & grandson of admirals, was a dunce at Annapolis, and continues to be stupid as a senator.
I would caution against the dunce at USNa stance as well. Most people around could not come close to graduating a service academy. Not saying he is a genius, but it’s like the old joke: What do you call the guy who is last in his med school class? Doctor.