A Story (or 2) for you...
My youngest Stepson (whom is now 16 but he has been my SS since he was 3) was/kind of still is the most stubborn kid ever! We got him his first bike over at our house when he was @7 yrs old...we ask him if he knows how to ride it, he says yes of course he does and how he has been riding bikes at his mom's house for years, yadda, yadda....he gets on his new bike and proceeds to go straight down the driveway, head on straight into the parked car directly across the street! He threw his bike down and went and sat on the grass...I immediately snapped a picture of his pouty face!! It was hilarious! We still joke about his stubborn side and bring up this picture, even now at 16!
I have the cutest professional picture of my 2 boys with Santa...my oldest was about 3 at the time and he wasn't so sure about having to sit with Santa, so I just had him stand next to him and his face is priceless...he looks seriously pissed off! The woman was like, "should I re-take it"? I told her no...it was him and how he felt. I love it dearly!
~So to answer your question, Yes. I take pouty, crying pics of my kids sometimes! IMO, they are my children and I know them better than anyone...and its not like it is being done with bad intentions, its to capture a moment in time. My youngest boy has the CUTEST 'angry eyes' I have ever seen...I LOVE IT!