AdNauseam has a clear definition of "good" ad networks [1]: with default settings it allows ads that obey do-not-track headers, as tracked by the EFF.

Of course in theory they could become some kind of evil authoritarian censor board. But that would cause a lot of users to jump to the next best extension. It's not really a big threat.

>what happens if they think every ad network that fits my user-base is evil?

That sounds unlikely, but if that happens and you are too small to manage your ads yourself, you should find a different revenue stream. Or start an ad network, since you've obviously just found an under-served market niche :)

1:https://github.com/dhowe/AdNauseam/wiki/FAQ#what-is-the-effs...