You'd think if that were the argument then the police would have been against ShotSpotter. That wasn't the case. The police were all for it, because many of those "wild goose chases" turned out to be actual shootings. Many (but not all) of the arguments against it were because the opponents didn't like the "overpolicing of Black neighborhoods".
Also, expecting ShotSpotter by itself to decrease gun violence is not realistic. ShotSpotter is a tool. There are many tools that have to be used together in order to reduce gun violence. If Shotspotter leads to felons being arrested with firearms (it did), and the DA simply dismisses those charges, that's not on ShotSpotter. ShotSpotter did what it was supposed to do. The DA failed on their end.
In Fayetteville, ShotSpotter was renewed and homicides are down 50% with violent-crime in general at a 10-year low.