Beyond that, the crackdown has been felt the most in the shutting down of art and show spaces in Allston warehouses which are zoned appropriately. Granted, the proprietors of these spots don't bother with permits from the city / following fire code, and often encourage or engage in illegal activity beyond simply hosting loud music, but these venues are definitely NOT disturbing neighbors (the neighbors in this case are generally rehearsal spaces for punk bands and other similar performance spaces).

The fire code is no joke. People used to die in batches of hundreds all of the time before those laws and reforms were put in place.

You can use the same argument when you see a police officer working burglary instead of homicide, or homicide instead of rape, or vice-versa.

The police, like the military, is a tool used to implement the policy of others; in this case, the policy is chosen by the jurisdiction's legislature, which is composed of people chosen by that jurisdiction's population. The police can (and should) prioritize which policy they implement most avidly, but if some things are going entirely undone that's something that needs to be handled at the legislative level, possibly by repealing or modifying the laws the police are charged with implementing.

And then there's the wars. Big, heavy duty crime hasn't "fallen" by any means, it's soaring from peak to peak more like.