What makes you feel valuable?

I was chatting with a friend this morning. She's a veteran BA/PM. She's really frustrated that the development team and business team that she's working with.
One point of frustration that she has is the business process and the computer application that performs this process is unnecessarily complicated. The thing that frustrates her is that there are people who take pride in the process' and application's complexities. They take pride in the fact that they have mastered, or are capable of using, this process where others need to suffer to learn it. The process is very valuable to the company so therefore they feel they are valuable to the company
This is not uncommon in IT. People get a big ego when they create something that nobody can understand. You hear a lot of hushed bitter voices snickering "If I ever decide to leave, they'd be screwed without me."
It's true to an extent. When you lose people with specialized knowledge it can hurt. When it happens, it usually isn't the end of the world that the person predicts.
I think this is a fool's argument though.
I would argue that making a complicated process difficult for other people to understand is no great achievement. It is true that there is some value that your process, and by extension you, will be to your company/customers.
First off, wouldn't you rather make a complicated process more simple? Aren't simple things easier to work with and understand? Isn't it easier to train people to work with processes that don't have a whole lot of special and/or irregular rules?
Secondly, do you want to be valuable because only you can support something you created? Do you want to be rehashing work you did five years ago?
Finally, think about what that says about your work and you. Unless you personally are there to constantly tend to what you built, it will fall apart. That really just says that you're not a very good designer.
Is there any profession where that attitude prevails? Imagine a mechanic who thought that way, a carpenter, or a doctor.
I, personally, would rather do new things. I don't care to support old applications. I'd rather not rehash the same issues I worked on a year ago. I'd prefer to get things right and move forward.
Instead of making a system so complicated and intricate that only you can make it work, how about making a system so simple and straightforward a non-techie could operate it. Wouldn't that really be the greater achievement?
Having the ability to create applications that work and are easy to understand, and more importantly, c is going to provide more career security in the long run.