And no, societal issues that we can't do shit about because there are already laws against them shouldn't be protested or at the very least should secondary because they dilute the message. But I can't expect from your particular group to understand what practical solution is or in fact to ever achieve anything. The Narrative™ is above all else.
but then
That is a police issue, that's what protests against police violence and corruption are for. The Baltimore police department is notoriously corrupt and people have protested against it. You pressure the officials by protesting against that particular precinct, or police in general. What you don't do is organize a protest about all the fucking issues in the world while at the same time your main message is basically "Fuck Trump, I can't believe we lost".
Which is it, or are you making this shit up as you go. The Baltimore police department, like the Ferguson police department and countless others, clearly violated their citizen's constitutional rights. But because we have laws against them, in this case the constitution, protesting against these departments is useless right?
You have this very weird, special fellow-like view on the topic. If the protest isn't 100% on an issue you deem valid, it's an aimless futile protest that dilutes the message. It shouldn't be surprising that a "women's march" focused on a variety of problems and issues facing women today. From sexual assault to abortion to birth control to the wage gap you don't believe in to...etc etc etc. Likewise every recent protest over the death of a slain black dude has been about violations of constitutional rights, corruption, etc etc etc...not just the murder of one person.