Wouldn't say accomplished nothing, they lost to eventual SB champs in '08...Lost to NE in '06 and '07 (Rivers was not really a very good QB yet. '06 was his first year starting and '07 NE 1 of the best teams ever)
'09 vs Jets Nate Kaeding blew that game for them.
Then from '10-forever he was just kinda irrelevant, just a weird career. Can't remember anyone else like it. Like he was in purgatory or something. Of course, some of the lack of team success for SD during this decade obviously had a lot to do with him. The sports media/fans couldn't even really be bothered to critique him though because it was the Chargers so who cares.