No sense for whom? With private companies, it makes great sense for stockholders or corporate executives trying to extract as much current value from the compa

No sense for whom? With private companies, it makes great sense for stockholders or corporate executives trying to extract as much current value from the company as is legally allowed (or can get away with). Future value is of much less consequence to them. That's exactly why they have done so historically and continue to do so. With government agencies, the incentive is similar, in that prefunding means they have to public funds today. It's much more attractive to leave the problem for future politicians, literally decades later. However, if the USPS actually has to prefund its retirement plans, then it's fair to say that's an onerous regulation, compared with private industry, which doesn't, no matter how many "should"s you throw at them.