In private markets you can only make money if you produce something other people value.
But in the presence of artificial rents like this drug enforcement subsidy, the link between "make money" and "produce something of value" is broken. It is an artificial rent. And the resources devoted to seeking the rent, to the extent that such resources are taken away from other useful purposes (preventing property crimes, protecting citizens) are wasted.
Rent-seeking isn't really about the rent, which is a transfer. The cost of rent-seeking is the wasted resources devoted to capturing the rent.
Emphasis mine.
