The standard knee-jerk reaction of wailing at the passing of yet another little-spoken language always fails to take into account the other side of the equation: a huge number of problems on this planet stem from the fact that people speak different languages and profoundly fail to understand one another.
Paying the price of losing little-spoken languages and the bits of culture that tag along with it is a very cheap price to pay when compared to what is gained.
I strongly disagree with whatever led you to believe such a thing.
That was the original thought behind Esperanto... the idea was that there was strife between different groups of people because they speak different languages, and that a universal language would solve this (or at least bring them closer together). [1] Whether this worked out or not is left as an exercise to the reader. ;-)
How much of this do you really attribute to different languages? By and large everyone in America speaks English, but the past couple years in particular has very much demonstrated that we profoundly fail to understand one another. To me the language is obviously important for literal communication, but to an extent pretty irrelevant to the communication barriers in society.