https://marco.org/2010/09/01/googles-adsense-click-solicitation-policy-of
Google’s AdSense [click solicitation] policy of Don’t Ask/Don’t Tell is hypocritical, but then so too are most of Google’s other opaque policies. Everything with Google is algorithmic yet the algorithm is never defined. Enforcement, too, follows yet another unpublished algorithm. Google seems open to the idea of its partners being a little bad while never defining exactly how much bad is too much bad. Presumably we’re deemed not smart enough to understand.
Google benefits from click fraud so it tolerates it to some degree, with that degree never being fully defined, either.