[kevingadd]

In this context, the fact that the manifesto also violates the code of conduct makes it more likely that they feel obligated to act. If it were in a private chat or on his personal blog it would be much less of a big deal. Similarly, people posted stuff like that in g+ and memegen comments frequently without getting fired. I think the scale and visibility is part of why he got a bigger response in general. Sending around a less controversial manifesto inside the company probably would've been fine - I think he could have easily just focused on the diversity programs and elaborated why he thinks they aren't working well, and that wouldn't have gotten him fired or caused such a controversy.

For whatever reason, he decided to go in deep and lay out his entire worldview on biology and gender traits, ensuring as much disagreement and conflict as possible. Whether this means he intended to cause problems or he just didn't understand how to complain constructively is a big question...