I think what they tried to do was to put a lot of girls with guitar in there (knowing that it had worked for the last two seasons with the guys) to get a female winner like they wanted. But the girls seemingly didn't catch on, or were too similar to each other, and they lost three of these "girls with guitars" right in the semis (Janell, Lilly and Katelyn), then Didi didn't perform as well as they probably believed she would, so they were only left with Crystal. I bet they thought that Katie and Siobhan would be better as well.
The Grassy Knoll believes (and I believe it as well) that to get their female winner, they put a lot of guys in the top 24 who were all flawed. Even the four who are left are flawed in some ways. They like Lee and he's compelling in some ways, but he's not a good live performer/singer really. Casey is pretty and he's a good musician, but he doesn't have charisma and he's not savvy enough to know how to play the Idol game. Aaron is all wee and cute, but he's just not that good. Mike is a good singer, but he's old-fashioned, cheesy and his personality grates. And let's not talk about how Tim and Andrew were flawed, because it's pretty obvious.
So, yeah, they tried to manipulate the season to get their female winner, and it may (and should) work, but at the cost of a pretty bad season overall. So, I think the gender split could've worked if they had chosen 12 good girls and 12 good guys, but it's not what happened. I mean, was that really the 24 most talented people they found? Let me doubt it.
So, seems Kris and Allison's duet won't even air on TV? This is a downer.