Yes, it's an incredibly complex topic. Most people without a strong background in finance pick up their education on the topic from oversimplified source, such as:

- their family/friends' opinions,

- Wikipedia,

- documentaries,

- movies like The Big Short

To be frank, unless someone has spent a significant amount of time doing hard research on the topic or is a professional in the industry, they shouldn't assign any confidence to their opinions about what caused the crisis. They can agree it's bad and shouldn't happen again, but beyond that most message board conversation is simultaneously prescriptive, uncritical and conflicting.

In this particular case, we're seeing people talk about the topic who are evidently unfamiliar with the legitimate use of risk pooling in finance. It's rather too complicated to be summarized in a few paragraphs on HN.