Raiders close to resignin Asomugha

[Macken]

The Sacramento Bee hears that free agent Nnamdi Asomugha is "close" to signing a long-term contract with the Raiders.
It's hard to fathom why Asomugha would want to stay in Oakland, but this is the rumor. An undisclosed L.A. radio station and RaidersBeat.com also say a deal is near. If Asomugha isn't locked up by Thursday, the Raiders will slap him with the exclusive-rights franchise tag, costing $11.718 million.
Source: Sacramento Bee

why would he want to go back to oakland when he can start on a SB caliber team?