In my experience, granted a bit limited but probably more than the average person has, these types of bullshit charges are generally thrown out. That, or they're held over someone's head, used to intimidate them into not doing other things. So it is more likely that these officers leveled a bunch of bullshit charges against folks that the DA didn't pursue, or that are being held in limbo to discourage them from, say, protesting and risking getting hit with new charges _and_ the old ones.

That said, I think we're in agreement that this is wrong. I'd just take it further and state that, if police officers file a charge, then I think they're obligated to do all the extra work to see that charge through, maybe within a reasonable window like 30 days. Subjecting someone to arrest, physical injury, and a night in jail only to throw out a charge as unfounded should come at some cost to the officers who caused it. If coders, lawyers and doctors did only a quarter of their jobs, or made a bunch of work for others that ultimately amounted to nothing, they'd be fired.