One of the things I like about iron sights is that it forces you to be more patient and plan your shot a little better, at least for me personally.Even though I am chronologically experienced, I shoot competition pistol with open sights. I like the challenge and usually fare quite well against the younger competition. I hunt deer with Smith revolvers with open sights as well. I have rifles with optics, too. Just depends on the situation.
We always have an "open sights lever day" at the hunt camp each year, too. It usually lasts for more than one day...!
I have nothing against optics by any means, it's just currently my personal choice.