I was sceptical about the Contenders last year (particularly because it was used to replace a player who had qualified based on ranking rather than wildcard and hence IMO should have been given to the next highest ranked player rather than another glorified wildcard). However it actually worked out better than I expected, created a good atmosphere and a few close matches. The moment Sherrock beat Mensur I knew they would bring it back as a way of getting her involved without the embarrassment of picking her as a wildcard and seeing her get thrashed every week. The advantage of the Challengers is they can cherry pick local heroes for each event so you have Scottish, Irish, Dutch, German etc players in their countries and then where appropriate English[wo]men from the region to boost the atmosphere. Of course it isn't 'fair' on established pros who miss out despite being ranked higher but the whole PL system isn't 'fair' given it has wildcards already, you just have to accept it for what it is.
I had considered an alternative where you would just pick 8 challengers and make them play a qualifier event and the winner gets a full PL place. But that wouldn't give the same buzz as seeing a Dutchman in Rotterdam or a German in Berlin - which is also a way for the PDC to try and continue to grow overseas.
Whether you like Barry Hearn or not he is doing what it takes to drum up interest, money etc and that's the PDC perogative.