Making it as a public company is not mutually exclusive from being sleazy.

Those are some pretty bold accusations based on rather thin evidence. Are you suggesting that such a service is incapable of running above-board? Is there anything Yelp could do to prove to you that it is operating in an ethical and reasonable manner?

Yelp seems to have had a lot of bad press for this kind of thing and has had at least one class action suit, alleging extortion, levelled against it:

http://yelpscam.com/negative-yelp-press.html

A lawsuit filed against them is not proof of anything. That same suit was thrown out.

That's an awful lot of negative press. Seems quite possible there's something to it (unless there's some sort of conspiracy against Yelp).