People wont just boycott Clippers home games next year, they will boycott them on the road as well. What he did is unforgivable, and no one support the NBA again if they allow him to still be an owner. By not taking the team from him the league is sending the message that they agree with him.
Really? Don't be so naive. If no one is boycotting him now when the outrage is strongest, there's no way they do it next season.
People have the attention span of flies for most of this stuff, they wouldn't maintain it during a full offseason. If you need examples, just look at the fact that Sterling has done WAY WORSE and gotten away with it for years.