- Most of us aren't going to kill ourselves or others in case we screw up. The stakes may be higher for people working with safety critical systems, but such systems often have multiple safeguards.
- Most deadlines and time pressure are completely made up. So what if we don't deliver on time? It is not like the fate of the world depends on the new software version. It may be different for sysadmins though.
- We usually have some flexibility. We are not like bus drivers who will leave people stranded if we don't show up on time.
- Our skills are valuable, if you are somewhat competent, you are pretty much guaranteed to find work in your field. Maybe not a dream job, but at least something better than a minimum wage gig.
Maybe that's a combination of artificial pressure with a high concentration of people who have difficulty coping with stress. Anyways, I am not particularly stressed, and neither are most of my coworkers and friends working in the field. Some jobs look much worse to me: medical (people can die), construction (risky), art (highly competitive market), ...