Sabeur,
It is not the best way to do it and for customers it is not the best way either. If a website directory does not have the hosts paying money then they turn into a hobby directory that never is updated either.
The forums are a great way to find hosting reviews and there is no force advertising involved. However, if someone wanted to make money it would be giving on honest review like Dan does. Somone go create a web hosting directory based on reviews and not ads.
Good Luck with your search. And, remember some of the little hosts you find everywhere aren't that bad whether it is local in town or on forums.