For several reasons, he and Grace have a 3 year old daughter that don't belong in that mess. He also has a son who he has only known the last few years who got hurt and is in a wheel chair now, also with his first grandchild. He can't leave them in case he is needed. Also Grace makes no money or very little for what she does, someone needs to keep a source of reliable income. I know it was last minute, but it would of been better to unalive her character, they have made her extremely selfish for doing this.