Throughout most of my career reading and maintaining code got fobbed off on the new programmers and the less skilled. Maintenance programming has a bad reputation, partly because it requires reading and figuring out someone else's code.

Now I make a living reading and maintaining code no one else will touch. Lots of companies can't afford to rewrite a mostly-working system, or they can't take the risk. I found a niche doing maintenance work and now I enjoy fixing what other programmers have said they can't maintain. Freelance maintenance work pays just as well as green-fields development and has fewer customer hassles, too.