Not totally true. The building is much older than that. It was renovated in, what, 1994 or 1995? The Sonics left after the 2008 season - that's clearly not "less than years old at the time." Renovating a building built in the 1960's isn't the same as building a new building. I mean, every time any sort of facelift has been performed on PGE Park, it's still clearly the same ol' park. Ultimately, you can only do so much through renovation.
The OKC group didn't put much effort into it. Howard couildn't get the arena he needed, and the fans and local politicians weren't much help. Everyone knew as soon as Howard sold to the OKC group, the team would be gone. The city easily could have kept the team, but by doing nothing, they chose to let them walk.