Personally, I wonder if it's not an act of provocation on Iran's part. If they can get one of their ships shot at...or even better, sunk...they can turn to Russia and point to America's deceit and claim to need nukes to defend themselves. It's pretty clear that a couple of their frigates are no match for a carrier battle group.
This, of course, was the point of all of those shows where they blew up a mockup if a carrier.

We're playing checkers, they're playing chess.