It is more important for software people to know a wide range of subjects. Our job is to automate away the job of other industries, and every time we succeed we need to move on to a new domain and automate it. You should consider it a personal success when your current employer lays you off because the current version is good enough that they don't need as many people.
Your best bet to success in this industry is to know a lot about something that isn't automated enough yet.
