You make a lot of valid points, but let's be honest. The down trend for this team began before the super bowl loss. It was magnified by that fateful play, but remember how fortunate we were to even win that NFC championship against Green Bay. It was a hell of a comeback, one for the ages even...
Here is a little clip... It made me laugh so I recorded their commentary on video :)
The bit about Richard Sherman was great :D
https://www.youtube.com/watch?v=nhRQsm4kEFk