According to the article, blacks are stopped 600% as much as whites.
The NBPA say that this is counterproductive, and taking only the effect on crime prevention and detection into account, judge that the damage done to community relations outweighs the benefit of the extra checks and maybe blacks should be less disproportionately stopped, maybe 500% or maybe to the proportion suggested by actual crime rates across ethnic groups (which would not be anywhere near as high).
The outgoing president said that stop and search is having no deterrent effect on gun crime specifically, and that blacks should be stopped even more disproportionately, say 700%.
You could argue either way, although on balance I think that random stop and search with racial profiling is never going to be effective at combatting gun crime, cooperation to encourage more witnesses coming forward undisputedly would be.
I don't think that we need to fully liberalise gun ownership in order to keep the UK's population of mexicans down to a manageable level, but it's an interesting suggestion I suppose.