Why would they want to build a Redskins stadium so far away from DC? The distance would have a significant impact on attendance.
Ever been to D.C. at night...?? It's not what you would call, an inviting environment.
It's also quite a cluster. The old RFK stadium was quite the experience back in the day. Especially for a Cowboys fan
The only practical way to get there was the Metro.
The suburbs, & surrounding areas, are much more inviting to the fan base that can afford game day experiences today. NFL games are no longer inexpensive events. I have in my possession, my ticket stub from the '82 NFC Championship game at RFK. The face value of the ticket is $17 LOLOLOLOL This was a row 1 approx. 45yd line seat, that I sat in
You couldn't touch that caliber seat for less than 100+ times that amount today. The face value alone would be well over $500.
People that can afford these type of events, don't really want to walk through crime ridden areas to a venue. They don't want to leave their cars, & come back to it sitting on blocks either
With the exception of a couple neighborhoods, that are in the zip code, D.C. is a rough place just outside all the Marble, & Granite.