The horrors of the automation revolution have been on our collective mind for a long time. In the '70s this was one of my dad's favorite jokes: "It's terrible, my father lost the job he had for decades. He was replaced by a clever mechanical gizmo just six inches long. And then my mom got one." It plays on the fear of being emasculated by technology. Maybe that leads us to exaggerate the threat.
It's about stability. You carved a nice spot where you found joy and financial ... well .. stability. And now your life might go to the toilet. There's no guarantee that your next job will be
1. Fulfilling in itself
2. Provide the same income
3. Provide the same secondary benefits (colleagues, hours, boss, etc)
And.. automation is not even a guarantee that what your were producing is gonna improve (lots of chances it may but it can go the other way too: cheap commoditization)