Making "Grey's" a little darker

Seriously, why take one of the best characters on one of your headlining shows and move them out in before season four even starts shooting? Is it money? If you say it's money I'll start throwing things... from tv.com:

Taye Diggs will star opposite Kate Walsh in ABC's potential spinoff from hit medical drama Grey's Anatomy. The show will test the waters as a back-door pilot, an expanded two-hour episode of Grey's slated to air in May.

It will center on neonatal surgeon Addison Shepherd (Walsh), a character who has enjoyed a strong following from fans since she was introduced at the end of the hot surgical drama's first season.

It is understood that the back-door pilot episode will feature Shepherd on the verge of leaving Seattle Grace, a scenario that will be triggered if ABC goes with the spinoff for next season. There were no details on the character Diggs will play.

Grey's creator/executive producer Shonda Rhimes is writing the episode and is expected to shepherd the potential series. Meanwhile, Rhimes' other ABC pilot, about female journalists, has been pushed to a summer production start.

Diggs' casting in the Grey spinoff stems from a new talent holding deal he recently signed with ABC TV Studio, where Grey's Anatomy is based. He starred in two drama series for the studio, Kevin Hill for UPN and Day Break for ABC.

Addison can't carry a whole series and, as mentioned, Taye Diggs is TV anthrax. Find her another series if you want, ABC. Just don't do this. Can anyone name a spinoff other than Frasier that's worked in the past 15 years?