Because it would still be a 2 possession game at either 10 or 13. Now it's 3 possessions. Plus even if you don't get it, you force Iowa to drive 95+ yards in less than 5 min needing to score twice. They are not equipped to do that.
They're not on the road. It was already a two possession game a fg doesn't change that. Not getting the TD puts Iowa on their own 1. It was a good decision.