I think the main liability of Ronaldo is his selfishness and that he continues to make bad choices in big matches. Not that it has any impact on his numbers, because he scores a lot. But it may have a big impact on the numbers of his team.
Let's say he has an average of 9 shots per match. 5 of them are done in awkward situations, or in plays that could have a better goal rate if he continued the play on, crossed or passed.
That's why he always plays well against small teams(and I'm not talking about scoring, I'm talking about PLAYING well and make your teammates play better). Because he will have 8 or 9 chances and end up scoring. And against small teams, scoring usually means winning at Real Madrid.
But against big guns, even if he can score a goal while undeperforming (the same could be said about Falcao, Messi, Neymar, Aguero, etc...), he tends not to play well overall. And why? Because against powerful teams he will have only 3 or 4 chances, and doing wrong decisions then costs a lot. Not involving your teammates too many times has some costs. We've seen this in many matches of Man Utd, Madrid and Portugal. Matches in which he ends up shooting from 40 meters, moaning when he looses the ball and getting fustrated. But his teammates are even more fustrated than him. He doesn't make his teammates better. That's a risk in certain situations.
I'm not saying he must be perfect, nobody is (not even Messi), but other than scoring a goal here and there he doesn't have real impact on big games, he doesn't own the flow of the match, he hardly decides big matches by passing, he hardly creates his own plays. Add to that his poor tracking back in the wing and against big teams you can see why Ronaldo never seems to shine completely, and that's what the article is about.
On the other side, let's take Messi for a brief and easy comparison. Messi didn't score any goal in the 5-0 against Madrid 2 years ago, but he was the key player of the match, doing 3 assists and driving defenders mad. When was the last time Ronaldo had that kind of impact on a big match? And without scoring?
Take the example of free kicks. He has a very poor goal rate on free kicks (he was around 50th in La Liga in this department last season). Ozil, Alonso and Ramos are great free kick shooters with much better goal averages, but they can hardly shoot. How many goals has Madrid lost by allowing Ronaldo to shoot them practically all?
The fact is that Ronaldo limits his impact to goals, and off the ball he hardly contributes to the team in any form.
Note that he continues to be an awesome finisher, and one of the best finishers I've witnessed. But too many times he thinks first of himself instead of the team. He probably lacks the skills to make his teammates better: vision, tactical sense, good off the ball movements.
He's a superstar! The problem is people trying to compare him to Messi. This comparison has no sense at all. Messi is a playmaker, a finisher, a winger and a teamplayer at the same time. Messi can decide a big match by scoring, assisting or simply dragging defenders out of position, or delivering killer passes, or dribbling everybody. The impact of Messi in a match is brutal, no matter if he scores. He has the tools to make himself and the team shine.
Ronaldo only has the tools to make himself shine. That's why on big games this can be a double edge knife.
All hail the Greatest!