Some places do exactly this. I think the idea was that, with any kind of profiling, it would be easy for drug gangs to figure out who to use as mules. And with

Some places do exactly this. I think the idea was that, with any kind of profiling, it would be easy for drug gangs to figure out who to use as mules. And with any judgement, they can pressurise the guy making the call. But a lottery machine everyone can see is harder to defeat.