The problem here isn't the science, it's the pork.
Pork has nothing to do with it and the science isn't all that bad.
The problem is that SPOT is a diet-version of Israel's behavioral screening program, which is what makes it a waste of money.
SPOT leaves out the naked profiling that Israel uses and it also completely neglects the intrusive (and lengthy) questioning of travelers.
Basically, the two pieces that make it at all effective.
To summarize, the Israeli system could never be fully transplanted into the USA because
1. It profiles based on race, religion, and country of origin
2. It is manpower intensive
3. It puts security before anything, including your family of 5 missing their flight.