Did you ever think about wich language is more important nowadays? Everybody knows English used to be the most popular language, but today, anothers languages are asking for a place. French or Spanish are chosen by young people as a second language, instead of english. In fact, there are more spanish-speakers than english-speakers in the world, the spanish population is bigger, however the biggest business were made in english. So, the biggest companies are english-speakers.
Also, in my opinion, English used to be easier for a few people to learn it than another language. Learn chinese or spanish could be more difficult if you didn´t learn it when you are a child. For a lot of people could be a problem to deal with learning a new language...
So, in my opinion, Learning Spanish or French could be very interesting in the future but today English is more useful and comfortable in the current world.