I'm all for employee self interest. Yet I still think it makes sense to follow (most of) the article guidelines. Even in companies that treat employees poorly.

Here's why: it is in your own interest to leave good impression, for the obvious practical reasons. A hearty "screw you, idiots!" might feel good for a moment but it won't do any good and ultimately hurts your own interest. Jerks do not change because of feedback, they might change in response to people mass quitting.

If you want to get even do it by a) being awesome somewhere else and b) keeping the bozos unaware of the reasons why people leave in droves.

Yeah, b) contradicts the article - IMHO honest feedback should only be given to those who can take it and what's even more important, you should only consider quitting after your feedback falls on deaf ears.