I'm not saying that city management (politics?) was not a problem with Detroit. But the problem that I have with Hiroshima / Detroit comparisons is the following. Unlike the States which has room for citizens to relocate if they need to, the island of Japan has limited space for its citizens and the Japanese people probably had to rebuild Hiroshima out of necessity imo.
No Amish in Japan.
Detroit could be rebuilt too... but there’s no reason to bother because the same people who destroyed it would destroy it again.
If tomorrow every Democrat had to move out of Detroit - and the land was given to conservatives of ANY ethnic group - the city would rebuilt itself.