.. there were already 600 or so links to all kinds of porn & pharmacutical tripe on it, would you submit to it? Hypothetical question.
If it has 600 links on page it will not help anything over 100 links google does not rank well or not at all
No i wouldn't put my link on it. 2 reasons. 600 outbound links gives it little juice with SERPS. And i don't associate with those niches. Even though i won't get punished for it, i act off my ethics and morals.
Only if the links were seperated into categories on seperate pages, like a real directory. But if they are all on the same page, no thanks.
If you're not comfortable with it then don't. I wouldn't for the same reasons people have already mentioned.