Well it was pretty obvious that Kendra would win. The producers had been pimping Kendra for the last 3 episodes.
As for the Apprentice decline, I think the second season killed it. The second season wasn't horrible, but clearly several things went wrong.
1). Almost none of the contestants seemed qualified to run one of Trump's companies compared to the first season. The women in particular in the second season were horrible. It seems the second season they were just casting for personalities.
2). Trump also got even more full of himself (if that's possible). His firings started to make less sense as it seemed he made a lot of decisions just to stir up drama. It ended up giving the show less credibility. He also started to let the contestants influence his decisions. Teams were literally trying to vote people off and Trump fell for it on several occasions.
3). The sponsorships started getting out of control. The first season had a couple, but you didn't have the entire show sucking up to a corporate sponsor. By the second and especially the third season, it's hard to tell the difference between the commercial breaks and the actual show.
Season 3 was actually better than season 2. Issues 1 & 2 were better however the corporate sponsors got much worse. Also, season 3 followed much too closely to season 2. Even though this season had an interesting concept, virtually no anticipation was built.
Hopefully the ratings decline (over 40%) will humble them some. The show wasn't suppose to be a run-of-the-mill reality drama, but now it's become one.