Less traffic in the suburbs? In what country? In US suburbs, nobody can take public transportation anywhere, so the streets and highways are choked with single-occupancy cars. The transit infrastructure is all about getting from the inner suburbs to the city center. Suburb-to-suburb commuting by public transit means turning a 30-minute drive into a three hour trip downtown and back.
Back when the transit systems were designed, they never anticipated the commuting patterns we have today.
Also, reverse commuting isn't just for hipsters. Outer-ring suburbs are too expensive for low-wage workers.