But the fact remains that it doesn't make much logical sense as a requirement (to do background checks of people who go thru the same checkpoint as those who don't get background checks); if they were forced into a bad business plan by the government, they were still silly enough to stick with a bad business plan and pray that one day it would suddenly start to work.

As I mentioned in a comment above, Southwest currently has a process in place in several airports that allows you to cut in the security line sans background check.