I think the mentality is: if you can afford to party, then you can also afford to arrange your own transport (eg. taxi) home. Public transport running at night

I think the mentality is: if you can afford to party, then you can also afford to arrange your own transport (eg. taxi) home. Public transport running at night time will be inevidently be subsidized by either day-time riders or tax payers, due to the much lower density of riders. Then, why encourage people to stay out late... In northern Europe you often hear the safety argument for affordable night-time public transport - “without that people may catch a unlicensed cab or try to walk home and get robbed, or worse”. But in Tokyo you the risk of something happening to you even if you pass out on the sidewalk is very very low.