At the moment, spamming Google seems to be trivial with no long-term penalties if you get caught doing something nasty.
A simple rule (manually enforced on a case-by-case basis) that would ban your brand/domain for a year if you get caught breaking the rules would get Pinterest into compliance from day 1 for example.
Using ads/analytics/affiliate links as a negative ranking signal would make a lot of blogspam/listicles/clickbait disappear if their only funding method immediately makes them rank much lower below where they are no longer profitable.