I agree with the others who said 2009 was a better time. They let anyone and everyone up, regardless of age or gender.
It seems pretty clear to me that they aren't just bringing up young, enthusiastic fans. They're specifically bringing up conventionally attractive young women. I'm young, enthusiastic, and at the concert I went to, there were other under-30 fans who clearly would've liked to go up to the stage, but we were all stopped by security. The only people who were allowed to the stage were those with front row seats and tall, thin girls in tight dresses who were corralled in front of Lindsey.
So I can't really buy the excuse that security wants enthusiastic people at the stage, unless they're dressed up and attractive and placed in front of Lindsey. If they wanted fun people in the front, they could try expanding their criteria.
__________________
"Or maybe she's a witch, who transcends the boundaries of time and space, and traveled back to 1981, for her own reference."