From my experience, approving links is a headache. But if you be careful and moderate to perfection, the hard work pays off. You can gain popularity and for a well managed directory, you can have a featured link handsomely charged. The monetization of the directory can get better and better.
We all get spammed heavy on directories and it gets to a point when you don't want to review anymore and leave the directory the way it is especially if the directory software is old and does not have mass delete button and deleting 1000 submissons when done one at a time isn't easy and the mouse ofcourse doesn't last long. Still i would say that directory should be free in my opinion(so that i can submit).
I agree with you , and in my opinion cars should be free as well ! - everything for free, hosting for free , domains for free , electric for free, even no taxes . Like in heaven I agree with you ,
It's part of the directory game. If you want to run a quality site, you're going to end up deleting way more submissions than you accept. It's been that way ever since I started in 2006 and probably was that way long before that.