They need a Ben "type" to pull off the bachelor concept, though. If they found someone edgy or deep, many of the women would find there's no chemistry. The worst thing for this show would be mass defections at early rose ceremonies. As soon as a couple of women turn down a rose or start bad-mouthing the bachelor, it's an entirely different show.
I suppose Fleiss has some protection built into the contracts - maybe the women aren't allowed to reject a rose without specific permission. But it would still be obvious on the dates if the women weren't hungrily seeking out "one-on-one" time.
Casting is so important to this show. Fleiss understands that he has to build the sorority, yet invite a couple of women like Courtney to keep things interesting. And he has to be very careful to cast a specific type of bachelor who is so even-handed, non-intellectual and masculine in a certain way that the sisters remain all a-twitter.
Unfortunately, the result of this casting is a final pairing that simply doesn't work from a marriage perspective. Fleiss doesn't mind because it gets ratings. Ultimately, in the world of reality television, he has produced one of the very few true winners.