I know you don't follow the Seahawks, so I will excuse your ignorance, but just take a look at the Seahawks second half of the season and tell me why we can't win in Atlanta, the second the Hawks opened up a playbook for Wilson, we have been as hot as any team in the league. Take a second and watch Russell Wilson play, the Falcons defense is nowhere near where the niners are defensively. Should be a good one. But the Seahawks are primed for the playoffs.
Yes, I do think the Falcons can beat the Seahawks in Atlanta, particularly if they have to play at Washington the week before, that's a whole lot of travel. The Falcons have lost 3 games at home in the last 3 seasons, we are undefeated at home this year. The Seahawks are 3-5 on the road this year, for whatever reason they are not a very good road team.
The Seahawks, they don't play well in domes. They're 0-3 this season when playing in a dome, losing to the Lions, Cardinals and Rams(hardly world beaters). I also think losing a starting CB to suspension will also provide a challenge to the Seahawks secondary when playing Atlanta. I don't believe you cover Jones, White and Gonzo for 60 minutes. They would have to blitz heavily and Ryan has insane numbers when being blitzed.
I can't honestly recall the last time Seattle beat the Falcons. I know they have never beat a Ryan led Falcons team.
In the end for me it comes down to the QBs and coaching. Atlanta wins both of those.
So to sumerize...
Possibly over 5000 miles in travel
Playing a rested team
Playing on the road(3-5)
Playing in a dome(0-3)
Falcons undefeated at home
Missing a starting CB