C'mon the Cassioppi angle is silly. Does any ranking service currently have him ranked? I guess there's a slim chance he's back, but right now the assumption has to be he won't be.
I don't think they're being inconsistent here. They're not dropping guys "due to inactivity," they're dropping guys if other guys do have activity that gives them better resumes. That's what happened at 125, where Provo beat the same guy that Camacho did to get his #1 ranking. No one is going to pass Fix unless they beat Vito or Crookham, and no one is going to pass Hendrickson unless they beat Kerk.
Now I do think at some point some of these guys that haven't wrestled a match should not be in the rankings at all, but that's a different argument.