He is definitely not a legend for Juventus Turin. If that is called a legend, then what would he be for Real Madrid?
Ronaldo score hundreds of goal for Real Madrid and won 3 Champions League with Real. I am sure he deserves to be called as a legend in Real Madrid. Even you dislike him, you can not deny his contributions and achievement there.
That's for Real Madrid but maybe a little different to Juventus although indeed in this case there are other extraordinary achievements for Ronaldo there such as scoring more than 100 goals in less than 3 seasons.
Actually regardless of whether he deserves to be a legend or not but we also really appreciate what he did at Juventus because he managed to become a handful of players who could make his name in the Juventus record.