> Part of the reason is that public transit for whatever reason appears to be unusually sketchy in many places in the US.

Police and policing culture is heavily biased in the United States to the protection of property and the interests of capital, so it makes complete sense they wouldn't give a fuck about keeping public transit or spaces that aren't highly trafficked by the wealthy very well protected. Maybe a little tinfoil hat, but if you take that into account, I think it makes perfect sense.