Van Basten failed to score a single goal in WC games. By contrast Klose has scored 14. Yet, no one would be stupid enough to compare van Basten to Klose, the gulf in class between them is huge. Arguably, the only centre forward in the history of the game whose legendary status is comparable to van Basten's is L. Ronlado. Klose shows that the importance of the WC performances shouldn't be over estimated.
Greatness in football cannot be objectively measured. The key thing is what people think. If the majority of fans think that Messi is up there with Maradona, no facts about his (lack of) success in international games would reflect on his legendary status. And if Messi goes on to perform at the same level for the next 5-6 years and wins on the way another 2-3 CL titles, you can bet your house on the fact that most fans in the world will consider him as great a player as Maradona, if not better.
I agree to a point, but as you said it's what people think. The bottom line is more people's opinions rightly or wrongly are swayed by what happens in the WC, than the CL.
If not then Klose would not be considered in the same terms as Klinsmann and Muller. But he is Germany's all time record goal scorer in WC's, which is a big achievement in itself, and regardless of his club achievements who can say he doesn't deserve it. Proven consistency over multiple tournaments and not always in the strongest German teams.
However you try and dress it up, the WC is still the biggest event in football, and like it or not, logical or not, people remember who performs well in them. For the same reasons the EC is a bigger event than the copa America because of the increased western coverage, so the likes of Van Basten and Platini are remembered for their triumphs in that comp, regardless of never reproducing at the WC.
By the same rule you could argue that Klose is proof that winning CL's is unnecessary if you can perform on the biggest stage of all. He has achieved legendary status in World football because of his contributions to the German national team. His club record is almost insignificant due to that achievement.
Pele, Ronaldo, Zidane, Maradona not only won the WC but played in more than one final, and were instrumental to their teams victiories.
Messi is not playing with a group of shit players in the current Argentina team. FFS if our lot was called the Golden Generation then feck knows what league that puts Argentina's current squad. I don't think it is unfair to expect Messi, as comfortably the best player in the world to have at the very least a very good WC, during his career with him proving himself on the biggest stage of all by inspiring his team to at least one final.
The same applies with C. ronaldo really, he needs to start inspiring that team as his talent suggests he should and like he does for Madrid. there is absolutely no reason whatsoever why Messi and Ronaldo cannot put their marks on the WC stage. The only players regarded as the greatest who didn't, never even got the chance to play in one. both Messi and Ronaldoi have the chance to cement their greatness beyond any dispute, they just have to take it.