Yeah, an empathetic person would understand how and why the person is feeling the way they are and acknowledge it. There can be of course legal repercussions to going off on your employer, but even a "yeah, that's now how I would have done it myself", etc can show that you actually do care.

If somebody you know was dumped recently and is saying negative things about their ex, it's perfectly fine to "agree" or commiserate while they process and go through the stages of grief (ignoring any issues like their ex being family, etc).

The author reads to me like one of those perennial "think positive thoughts only" people that think that'll get them success.