I'm puzzled as to why its such a mess in the US, even in areas with "good" public transportation, compared to other nations. I lived in Japan for several years,

I'm puzzled as to why its such a mess in the US, even in areas with "good" public transportation, compared to other nations. I lived in Japan for several years, and the subway/rail/bus systems are wonderful. Easy to use, reliable, clean, and no issues the mentally unwell or homeless bothering you. Is it cultural? Or is it a matter of political/economic policy? I have no idea, but I'd kill to be able to bring it to the US.