Knowing that security requires a "multi-layer approach" , I feel the deterret effect of dog/handler teams wandering (actively seeking or not) around a terminal cannot be underestimated.
I am far more comfortable in European airports/train stations that have strolling soldiers/LEOs with AK-47s and dogs than the current rigid, invasive and predictable TSA process. Throw a metal detector with the bag screen and IMO we've reached a reasonable risk threshold.
The TSA screening process is simply polarizing now. Shrink the staff and make it more nimble.
Call it "continuous improvement".