For me, Rooney is definitely a club legend. He burst onto the scene as a very young boy, and was a tremendously exciting, and important, signing for us. He was the best English player of his generation and, for at least a few years, one of the best players in the world. He was selfless with his positioning on the field, often playing out of position in order to accommodate others, and making us a better team. He was a major contributor to many successful seasons. He finishes as the club's all time leading goal scorer. Yes, he likely should have gone earlier. Sir Alex knew it, and put Rooney's departure on a plate, but in the wake of his retirement Moyes (and the club) bottled it and gave his a new contract. It shouldn't be forgotten, however, that over the past couple of seasons, Rooney was quite graceful in being transitioned into a bit part player. Many others would have made waves, but Rooney kept his mouth shut. By any reasonable standard, he's lived up to his potential and deserves to be remembered fondly.
That said, it's perfectly fair to not have the same affection for Rooney as other club legends. I don't. He twice (I believe) asked for a transfer, publicly questioned the club's ambitions, and suggested that he would be prepared to move to City.
In any event, Rooney has provided some wonderful memories. I'm glad he's returned to his boyhood club. I hope Everton fans welcome him back with open arms, and I wish him all the best. It would be nice for him to find some success, and end his career with his head held high.