Speaking only for myself I'd say because older women have an idea of what they like, know how to achieve that goal and not about the bullshit, games or trying to get money out of it. They want you to come in and handle tour business with whatever kink is agreed upon and then go about your business until the next time.
I find that today's "younger" female they are about trying to make money, be famous, and they are not as open, willing and no holds/holes barred as older women.
Again, just my personal take on it. Go get whomever you desire and make it work. Life is too short.