What's so crazy about that? Was only about 11 years old when production ended in 2006, not much older than where the Playstation 2 stands right now (Will be turning 10 in March of next year). The platform was still seeing new game releases in 2005 (And maybe 2006 outside of North America?), was still seeing games recieving new print runs in 2008, and hardware and games were still widely available on the used marketplace at retailers like GameStop until recently (And still are at Canadian locations).
Hasn't been very long since it ceased being a commercially viable console.
I'd say 2008 sounds just about right where I felt like it had ceased to be a commercially viable platform, moving it into the classic gaming category. It wasn't really the previous generation any longer since many people were beginning to move into this current one in large numbers, retailers were beginning to phase it out of their used merchandise inventories since mainstream secondary sales of it were drying up, the last remnants of new merchandise were drying up, etc.