It's not as if these places are impossible to access. The existing bus routes are just not well planned for this trip. These journeys are both less than 15 minutes by bike.
I'd be much more scared to bike in Greensboro than in Manhattan. Drivers aren't used to bikes and the streets in some areas are poorly set up for biking (no shoulders, many lanes in each direction, high speed limits, so you have to cross four lanes of traffic with one a highway entrance to make a left turn).
As kaitai & teddyc, mentioned the roads aren't as bike-friendly. Now trying to be a mother with kids in tow trying to bike a total of 30 minutes, in a not bike-friendly area, to the grocery store and back.