Usage of "of"

I've found following sentence from one of books about corporate crime. I would really appreciated it, if someone could provide me with the explanation of whey they use "of" before the events (bold text). Furthermore, my instinct say that there should be a relationship between the "of" before event and "matter of", though I'm not precisely sure about it.

It's not just a matter of companies making bigger profits than they should do, but of events which may affect the lives of innocent people, and yet very often companies, because they say they didn't intend to harm anyone, can avoid taking responsibility for the results of their actions.