Quad9 openly operate in threat intelligence: https://quad9.net/news/blog/protecting-millions-in-asia-a-ca...

City of London and Manhattan District Attorney’s Office suggests finance is a factor, so I'll hazard a guess that Quad9's telemetry is useful for protecting the interest of finance: e.g. learning of new/popular domains that might be tricking users/businesses into fraudulent activity.

Quad9 meanwhile have the remit to provide the best public resolver, including fighting cases as they do.