If a software department is constantly getting new people, (1) it's really easy work, or (2) it's hard work, and the company is wasting an enormous amount of money, paying programmers for months before they've learned the system well enough to actually be competent with it.
If your friend's work is anywhere near (2), your friend's boss is an idiot. On difficult projects, a skilled, veteran programmer is worth more than ten green programmers. With green programmers, it's not really software development... it's R&D. They'll spend 2% of their time actually writing code and 98% of their time researching, reworking the design, trying to figure out why the program doesn't work properly when they make a few changes, and bug-testing.
I'd tell your friend to leave the company. The boss thinks he's got it all figured out, but he's actually just a moron that's making everyone miserable. When the boss man realizes his software development/maintenance department is in disrepair, it'll be too late... the entire company will crumble like a deck of cards, and he'll be left to face the stockholders, his boss, etc. The company will have what you might call "alien ship" software -- the smoking husk of what was once impressive, but nobody knows how to fix it because nobody knows how it used to work.
You could also suggest that your friend try to get his/her boss to agree to a thought experiment. "You've just lost your job as boss, and now you're a developer. Here's your desk. Now start programming." When his boss complains that he doesn't know how, your friend can say, "Oh? You're new, huh? Don't know how it works, do ya? Well, you can read these 10 books -- make sure you take notes, by the way -- and then when you're done with that, you can read over project's design, then the code, then you can watch all of the meetings the developers had when making the software, and then you can read their emails, and then the code once again. When you're done with all of that, we'll let you tinker with your own copy of the program -- to see if you can work with the software without screwing it up. When you're done with all of that, you'll be ready to write your first line of code. See you in six months."