There are wonderful and world class universities in countries like Poland, Norway, Sweden and many more places across the world. You could be academically brilliant but say you know only English. Wouldn't it be great if you won a scholarship to study in Norway and could actually take up the offer if someone could teach you Norwegian? Imagine the world of opportunity that would open for you!
There are many MNCs headquartered in Germany, Netherlands, Japan, China etc. Knowing the language of the country where your company is headquartered could easily result in an assignment or posting in the HQ country. Not only would such an assignment be a feather in your cap, your work experience would be richer for it and could help you to climb the corporate ladder with greater ease than others.
Some languages like French, Spanish and Dutch are spoken in many more countries other than Spain, France and Netherlands. A working knowlege of one or more of these languages makes your travel so much more fulfilling and meaningful. To be able to sit with a local and swap stories, enjoy their hospitality and interact with their families would give you far more value for your travel dollars than the price of an airline ticket.