The boy was in Ronaldo's shadow for years. Ronaldo was the star and Rooney was the one working for the team and for Ronaldo. Eventhough young (18-23) and even though he was more of a team player, he was still scoring his regular 17-23 goals per season (for 5 seasons).
Now that Ronaldo left, not only that Rooney is scoring much more goals (20 so far in all competitions) but he also proved that he has the quality to lead his team, make things happen, which are characteristics of the world class players.
Whoever doesn't rate him high seriously has to learn a lot about football.