I used to iron almost everything. I kinda find it satisfying and calming. However since I'm now a part-time working mom I have cut down on it.
I iron my nurse scrubs. It makes me look more crisp and professional, and the extra dose of heat probably kills any germs that survived the washing.
Dh has been ironing his own clothes for years. He is very particular about his work shirts and apparently I don't do a good enough job with them. Fine by me. ;-)
I went to college with a girl from Indonesia. They had household servants and literally everything was ironed including the bedsheets and people's undies.