I internally translate it like this:

We have a transparent transaction network, which has a downside: bad actors such as state surveillance contractors we shall not name (also for states we dislike) use that weakness against people to inform compliance to exchanges and try to deanonymize wallets through attacking a node's p2p connections / timing attacks etc. Other bad actors may try to prevent transactions, attack LN channel closures, b10c's example of address poisoning.. all the things that basically subvert Bitcoin's integrity to any degree.

This downside/weakness happens to have an upside/strength though, because since it is a transparent network, monitoring isn't exclusive to large state sponsored corporations. We can look for bad actors ourselves, and even countermonitor the surveillance companies, out of the box or in this case, with not too much effort. A node with additional logging isn't insanely expensive, meaning we can grassroots monitor Bitcoin and become aware of threats as a "community". Grow our collective intelligence. Give feedback to developers when we see strange patterns that may be a bug getting exploited, or an attack or prelude to it happening. But if we don't do it, it won't happen.

Think of b10c's observer tooling as similar to a watchtower node that you have in your LND setup, but then not for your own LN channels / closure txs, but for the entire p2p network (or at least the part of it that connects to your observer).