The intention of prayer is to change or mend a situation. I know better than to expect that these people care about reacting meaningfully, but inherently “prayers” means that in an ideal world if the prayers worked this would not happen again. IMO!
That and praying for the healing of the families, which is also intended to mend but doesn’t due to their lack of action.
Though I hear you—their apathy is stark and anyone with a genuine drive to improve conditions like gun violence would realize that words are not a magic band-aid.