I wasn’t sure that I wanted a “big” iPhone as I was perfectly happy with the 4” form-factor. But if I was going to get a new phone and the new ones are bigger, I reasoned, I may as well go really big and go for a 6s Plus. On paper it made perfect sense.
Then I played with one in an Apple Store and I laughed. In practice it was comically big. I really didn’t want a phone I could only realistically use with two hands.