If vicious wanted to just kill spike he would just use a gun its not about pride like killing someone with a sword. Spike knew he was gonna die, still went to syndicate hq soloing everyone.
Spike knew trying to kill anne's killers or who ever showed up at that store had nothing to do with anne's murder still stayed risking julia's and his own life.
Both shin and lin sacrificed their lives for vicious and spike for no reason what so ever.
Sometimes life without something or someone is really pointless, may be these are all that matters for someone.
Thats somewhat I think what happened here.