I have a thing about not being late, especially when traveling. In fact, when fly, I actually get to the airport a full two hours before departure - NOTHING screws up a trip faster that missing the first leg of trip. I usually get as much done in my down-time at the gate as I would at the office. Besides, Delta screws things up often enough on their own without my adding to the chaos
I flew to Portland OR today, via Minneapolis - while waiting at Columbus, between planes at MSP, and while leaving the gate at PDX I saw four full-blown temper tantrums being thrown by people who had missed their departure at an adjacent gate for one reason or another. The TSA lines at Columbus weren't bad at all today, and were very short at Portland as I left.
I have co-workers who dismiss the airline recommendations of the 90-minute cushion, and on more than one occasion I've had to pinch-hit or re-arrange meetings because they missed their flights. It's a major pain in the ass, and I'm not shy about telling them so when it happens.
I know there ARE occasions when stuff happens beyond your control. But - what are you going to do with the extra few minutes you gain with a last-minute arrival in light of lost time and ticket change fees? (OK - sex is a good excuse - if that's all the time you need!