I book MCT (35 Min) in ATL all the time and have never missed one. Most are at 6 AM when we almost always arrive at the gate early or after 9 PM (not connecting to the last flight). I've had 9 of these connections so far this year. I had 24 last year without a miss.

BUT, I was in F or C+ for all of them and I know ATL.

If my wife is travelling alone, she knows ATL and wants a 90 - 120 minute connection time. She'd rather spend a little time in the Sky Club than be stressed.