I've seen some thoughts about this:
- Some of the businesses claiming "Yelp extortion" actually deserve their bad reviews.
- Some of the businesses claiming "Yelp extortion" posted fake positive reviews. Unbeknownst to them, Yelp bots automatically detected and removed the fake reviews. Later, after rejecting a call from a Yelp rep asking to advertise, the business owner decides to check their Yelp page and sees that their fake reviews are gone, incorrectly deducing that Yelp is extorting them.