They had a good run. 2 Finals. 1 Championship and a loss in the playoffs without KG after beating the Del Negro Chicago Bulls in one of the best playoff series of all time.
KG changed the culture of two franchises, put his all into that first year and was breaking down slightly every year while still running the defense. They were a team with a small window and succeeded but obviously could have done more if they stayed healthy. I'm not going to say Perkins made that team what it was, but Game 7 against the Lakers probably would have went different if Rasheed Wallace wasn't logging big minutes.