Thinking about it further, I think you have stumbled on the biggest difference - both Fire and Ambulance services are primarily there for emergency situations, prevention is largely a different department and/or an activity carried out during quiet periods.

For most IT people, the reverse is true: our performance is generally assessed on how _little_ time we spend on emergency care, as prevention is preferred.

This leads into the classic dilemma over training: should we put time and effort into learning diagnostic techniques, and purchasing diagnostic tools, or should we concentrate on ensuring that disasters never happen? While many large organisations will be prepared to have a dedicated disaster team, is Google's approach of massive redundancy not an even better idea?