It might be true that some languages are not used as widely as English, Chinese and other popular languages. For example, some local dialects are used by a few hundreds of people in their tribes. Hence, some people think that the language itself is not important as even it goes extinct, it would only have impact on a minimal amount of users.
However, it is irrational to judge whether a language is important by the number of its users. Compared the numbers of uses with English, Hebrew is regarded as a lesser-known language, but no one would therefore conclude that it is unimportant. Because Hebrew is known as the original language of Bible, without understanding it, the meaning of Bible might be distorted. Similarly, Latin is considered a dead language as only several Christian members and students can speak it fluently; however, no one would neglect its influence on English. Until today, a wide range of Latin phrases and terms are still using, especially in the legal terminology.
Moreover, every language represents the corresponding culture. The extinction of one language implies the lose of an unique cultural. Throughout the century, thousands of archaeologists try to dissolve in mystery of pyramid. Due to the failure of handling the ancient Egyptian, numerous of puzzles remain unknown and hence archaeologists fail to further explain the ancient life of Egyptians.
To be concluded, every language has its existing value and the consequence of losing one of them is far beyond our imagination. Our offsprings might have to spend a considerable amounts of time on figuring out the die out languages.