I do have the right because I simply understand that Russia has a huge impact on the world as well as big communities in the USA, Canada, Germany, Israel, Lithuania, Latvia, Estonia and lots of CIS countries that even learn russian in their schools.
And Portuguese? Just because Brazil is big? Do u really think that argentinos care about portuguese when they speak spanish just like any other SA country?
Mandarin is the second "best" language to learn, you are right, but it really depends on the person as well. I personally think that an average EU citizen will not need mandarin as much as french or german unless he is thinking about to start a business. But if I had to create an "overall" ranking I would easily put mandarin on the 2nd place right after English