Nico >>> I have my answer ^^
I think there's two ways, two interpretations of every thing we can learn : pleasure and necessarity.
Japanese, for example, that I manage to learn for my own pleasure, is not necessary, not usualy spoken, if it's not in Japan, so I can understand that it's not taught in many schools...
But English, German and others are usefull, in life as on a CV. So don't take it the wrong way, I didn't said that we should forgot avery others languages, just because they're more or less spoken, but my, this ones are the most requested, no ?