It's not necessarily bad everywhere and for everyone - I think park rangers in East Nowheresville do ok. There's a base GS pay scale and then locality adjustments for different metro areas, and the big problem with the WASHINGTON-BALTIMORE-ARLINGTON, DC-MD-VA-WV-PA locality is right there in the name: WV-PA. They pretend that folks working in downtown DC ought to be paid the same as folks at some remote site in WV. So yeah, I believe that means a 31% adjustment compared to the base GS pay scale, when to be competitive with other DC area salaries, the adjustment probably needs to be more like 80%.
I know many, many people who commute daily from Pennsylvania and West Virginia to DC. York and Harper's Ferry are short commutes. I know more than one Bucks County resident who make the trip.