Hoarding Technology: or how not to secure your job

The technology hoarder is typically a male in his fifties who takes it upon himself to master a critical piece of their company's software and not share it with anyone else. Typically, the motivation for this type of move is the hoarder's perception that their mastery of the technology will assure them of job security.
This move is tragically ironic, it reads like an O. Henry story.
The move you make to ensure your job security ultimately seals your fate to be replaced at the first opportunity.
Why does tech hoarding not work? Managers don't like tech hoarders because it turns their bus number to 1. That is if a bus were to hit one person the company would be in danger. Does anyone want to stake the future of a company on the health of a middle aged programmer? I'm not trying to be prejudicial, but guys who work on computers typically aren't in the best health nor do they typically make choices that prioritize their long term health.
All it would take is a blocked artery and the whole company is at risk.
If my responsibility is an area with that kind of risk, my first priority is creating a contingency plan for the hoarder kicking the bucket.
Tech hoarding is unwise from a pragmatic standpoint because what it really is doing is creating a dependency on the company. All the hoarding will be for naught if the company goes under. Your skills are your greatest asset. When you work for a company, you are investing in it with your skills. When you tech hoard, you are betting all of your skills on a company. If you're hoarding, you're investing all of your skills in a company that has at least one tech hoarder. Is that a wise way to invest?
Tech hoarding is not a good idea from a technical stand point for a few reasons: Tech hoarding is a process of stagnating technology around a business need. And the need is not unique. Another competing technology will one day make it easy to replace whatever the need is that the hoarded technology is satisfying. That's what technology is for. Don't fight it, embrace it.
I know a guy who could be described as a hoarder. He had a script that met a very specific need of a company that I was working at. This was a daily need that hundreds of people had to do their jobs. What is the problem, well the script's ability to meet the users' needs declined. The growing constraints put on the script grew its complexity and the essence of its function.
A new way to meet the need was found. It met the users' needs better than the script ever did. The guy who hoarded that script found himself unable to add value to his company.
Here's the real tragedy of the situation. The script took so much of the guy's time he did not work on anything else. He also didn't learn new technologies. When he found himself out of a job, he also found himself unable to get another job.
How do you avoid this situation? For one, don't hoard technology. If you find that your value to a company is tied to a program, there will be a time when that company will find another program to replace your program and you.
Instead, try to do work that does not require your input once it hits its maintenance cycle. This is far more valuable than tying your job security to a program. For one, you don't have your previous projects bogging you down. People aren't constantly calling you asking how to get things done in your old projects.
By creating software that doesn't have a lot of secret tricks you're also creating a name for yourself. People will notice good code and they will want to work with the people who make good code.
Lastly, it's your name that goes on the code. Do you want to be known as the guy who writes really complex code that nobody can understand? Others aren't going to assume that you're smart, they're going to think that you're a fool!