This is a “grasping at straws” strategy, popular among Trump supporters because there is nothing else and they can’t follow an idea through to its obvious and logical conclusion *(see: the entire nonsense of this “war”).

I think it's more a failure to accurately assess the enemy. The Administration seems to have thought that the Iranian regime was weak and perhaps cowardly. Again, like a bully, rather than a hardened criminal. So that if we took Iran and "tuned them up" with a solid beating - a little of the old "Shock and Awe" = they'd either lose control of the country or capitulate and do what we wanted.

And then they didn't.

I've read a handful of conservative media discussions about Kharg, and it seems to be basically the same assumption. That if we seized Kharg, they would quickly either lose control of the country or capitulate. That they wouldn't possibly just continue the fight with asymmetric warfare - that this would force them to understand that they've lost.

I don't rule out the possibility entirely. I suppose it could be that ending their oil exports might be the straw that breaks the camel's back. If there were any intelligence to suggest that, I would think we would have bombed Kharg already, but it might be that circumstances have changed recently.

But I think that's unlikely. As you point out they've suffered a lot of damage already and haven't lost the ability or willingness to fight back. And this is probably an existential fight for the regime; they are unlikely to believe that giving up their nuclear program and their ballistic missiles and their control over Hormuz will result in them remaining in power for very long, after what happened to Qadafi and Hussein.

We'll see, I suppose.