People who work at heights usually have just enough fear of heights to not do something stupid. Those with no fear of heights tend to make fatal mistakes.
Source: 35 years of climbing and 10 years of industrial rope access :-)
To quote Jim Whitaker, once upon a time a famous climber and founder of a well known mountain guide company, "If you're not afraid of heights, I don't want to be on the mountain with you".
Hi, I've considered changing careers to rope access or similar for a while now. Can I interview you about your job? Please email me, see profile. (This request extends to other RATs reading this too!)
Source: 35 years of climbing and 10 years of industrial rope access :-)